SIX

Studying Nature

Lived physics

In its ancient shape, the cultura and medicina animi often reserved an important place for the study of nature. The knowledge of the self and the knowledge of nature stood in close relationship at the core of the art of living. For the Hellenistic schools, as Pierre Hadot has shown, the discipline of assent was foundational for the whole paideic program and corresponded to the practical exercise of logic (a “lived logic”). Conjoined with it was a “lived physics,” understood as a discipline of desire: by attentively studying nature, the inquirer gradually comes to self-mastery and submission to the god’s will.¹

In the first part of his Usefulness of Experimental Natural Philosophy Boyle expresses similar sentiments, filtered through a Christian understanding of man’s duty to his Creator, in a defense of the religious and cultivating value of the study of nature. He quotes ancient philosophical and patristic sources, biblical sages and Eastern traditions of wisdom, with which he shares the notions of nature as divine creation and of man’s duty to contemplate it and admire its divine workmanship. Thus understood, the study of nature is a way to “Improving Mens Understandings” and to increasing their religious devotion.² It is therefore most properly seen as a philosophy of God’s works.³ The understanding of the experimental study of nature as a religious activity was commonplace among the English virtuosi, and it, too, had Baconian credentials. For Bacon, philosophy performs a service to religion, which is expressed in our “consider[ing] and magnify[ing] the great and wonderful works of God” and in its “drawing us into a due meditation of the omnipotency of God, which is chiefly signed and engraven upon his works.”⁴ In his Usefulness Boyle approvingly quotes Bacon’s dictum that “a little or superficial taste of Philosophy, may, perchance, incline the minde of a Man to Atheism, but a full Draught thereof, brings the Minde back again to Religion”⁵ and places it among similar statements by Galen, Hermes Trismegistus, and Paracelsus. Similarly, in the Essay, Locke assures his readers that although we might never be able to penetrate the essences of things, the study of nature is a valuable enterprise since the “Contemplation of his [God’s] Works gives us occasion to admire, revere, and glorify their Author.”⁶

The consolatory works of practical divinity written by promoters or supporters of the experimental philosophy develop similar ideas. Thus, in Discourse concerning the Beauty of Providence (1649), John Wilkins advocates a work of patient and diligent observation of both nature and historical providence, seen as similarly complex structures of divine contrivance: such work has the value of an exercise for controlling passions and immoderate desires, for learning humility and submission to the will of God.⁷ In his Peace and Contentment, Peter Du Moulin also thinks that natural philosophy is the one science that “will be sure to stick unto the separat soul” since the naturalists (among whom Bacon, “my Lord of St. Albans,” is the prime example) deal directly with God’s works and are engaged in a “contemplation” that “perfects” the rational soul.⁸ In the apologetic conclusion to his Experimental Philosophy (1664), Henry Power paints the image of the new philosophy in similar colors: “Certainly this World was made not onely to be Inhabited, but Studied and Contemplated by Man.” The employment of reason in this course of study—which Power calls a “Rational Sacrifice” most pleasing to God (cf. Romans 12:1)—is what advances the essence of our humanity: it “transpeciates our Natures, and makes us little lower than the Angels” (cf. Psalms 8:5). It behooves us, therefore, as part of the duties we have as created human beings, to see to “the right management of this Faculty.”⁹

These texts suggest that the religious value of the study of nature as the experimentalists understood it rested on the idea of an improvement and growth of the powers of the mind. My concern in this chapter will be to show how Boyle and Locke develop this theme and how in so doing they elaborate a rationale for the role of the experimental study of nature in cultivating the mind. The key conception grounding this rationale—which both philosophers maintain is equally supported by reason and revelation—has to do with the relation between the created world and the human mind. In brief, the conception is the following: There is a wise order and contrivance in the structure and government of the world. We have some ability to discern that order and contrivance, although it is beyond human capacity to comprehend its full scope and inner recesses. There is, then, both a match and a disproportion between mind and world. The notion comprises both the claim that the human mind has some ability to discern the complexities of the whole since it is meant to engage in that discerning activity, and the claim that there are vast regions of it that remain obscure to the mind. This conception—which combines ontological and anthropological tenets with a prescription for the legitimate conduct of the mind in the pursuit of knowledge—informs both the methodology of experimental investigation and the natural theological framing of this type of study.

The disproportion between mind and world indicates that knowledge of nature cannot be the result of metaphysical speculation but must come with information from sources outside the mind, i.e., from the observed world itself (the stuff of “experience”). On the other hand, such knowledge is possible, at the level permitted to the human faculties, owing to the match between world and mind. Nevertheless, one caution that the disproportion entails is that natural knowledge can never be complete and is always in need of revision. Legitimate natural inquiry, therefore, is such that it does not seek the security of definitive answers but is continuously resumed. Similarly, the match between mind and world makes it possible for the inquirer into nature to discern—to some extent—the divine attributes expressed in creation and thus to engage in what was to be called “physico-theology.” But it is actually on account of the disproportion that the mind is said to be able to become aware of and admire the ultimately inscrutable attributes of God, as well as to acknowledge its duty to try and grasp as much of them as it can. Here, too, the search should never be arrested. Thus understood, the search is said to involve a renovation of the mind’s powers, both cognitive and affective. From this perspective, I will argue, experimental methodology and physico-theology are construed as transformative exercises for the inquirer’s mind. I will also suggest that, owing to the value placed on the always resumed search into nature and into the divine attributes expressed in it, assumed as the duty of a Christian philosopher, the disproportion in question is actually, in a sense, part of the match. It is this nuanced understanding of disproportion that grounds the idea of the virtuous experimental search, which informs both natural philosophical inquiry and natural theological exercise.

This is also to say that my emphasis will be on the figure of the inquirer into nature, rather than on natural philosophical methodology and natural theological argument for their own sake. In fact, the suggestion will be that an approach from the point of view of the inquirer is apt to add important dimensions to methodology and argument, and to show how they are moored to the two philosophers’ general concern with the rightful conduct of the understanding.

The appropriateness of disproportion

In chapter 4 I claimed that Boyle’s paideic understanding of experience, as epitomized by the virtue of docility, rested on a foundational view about the fecund richness of the world and the ignorant but teachable nature of man’s intellect. The fecundity of nature, it will be seen here, is a notion that Boyle associates with the divine attribute of wisdom, which grounds his conception of nature as an exquisite structure of interrelations. It is in explaining what he understands by God’s wisdom that, in his Usefulness of Experimental Natural Philosophy, he introduces the notion of the “Aggregate or System of all Natural Bodies.” The image of the clocklike or engine-like “system” of nature seems to be an elaboration on the biblical reference to the “manifold wisdom of God,” which he cites several times.¹⁰ The aim of this text is to defend natural experimental philosophy against accusations of atheism, and a considerable part of it is dedicated to the detailed (one might say pictorial) illustration of the “curious Engines” and the “skilful Contrivances” of which the “exquisite and stupendous Fabrick of the World” is made.¹¹ The metaphors of “system,” “aggregate,” and “engine” are of course apposite to Boyle’s understanding of the world of nature as a supremely complex mechanism. In his later Free Inquiry into the Vulgarly Receiv’d Notion of Nature, he develops the image (while including perhaps unexpected organic analogies):

I consider the frame of the World already made, as a Great, and, if I may so speak, Pregnant Automaton, that, like a Woman with Twins in her Womb, or a Ship furnish’d with Pumps, Ordnances, &c. is such an Engine as comprises, or consists of, several lesser Engines. And this Compounded Machine, in conjunction with the Laws of Motion, freely establish’d and still maintain’d, by God among its Parts; I look upon as a Complex Principle, whence results the setled Order, or Course, of things Corporeal.¹²

This picture, Boyle says, is in conformity with a “probable” conception of the creation of the world, which builds on a scenario already announced in the Usefulness: in his “infinite Wisdom and Power,” God created a universal and undistinguished matter and established the rules of motion whereby matter became divided into parts characterized by various sizes, figures, and relative positions. By God’s initial guidance, these parts in motion, together with the “seminal principles” of the seeds of living things, came to form the world as we know it. By God’s continuing guidance—his “ordinary and preserving Concourse”—the laws of local motion effective among the parts of matter are maintained in operation, so that the “great Construction, or System and Oeconomy” of the world is preserved and the species of living creatures are propagated.¹³

According to Boyle’s “corpuscularian hypothesis,” the various parts of matter are characterized by the “mechanical affections” of shape, size, motion, situation, and texture, in terms of which their various qualities and powers may be explained.¹⁴ The parts are, moreover, so closely interconnected that any one part can be what it is only because of its relations to the other—neighboring or remote—parts of the “great Automaton.” Any such part, as Boyle’s experiments with the air pump illustrated, “needs the Assistance, or Concourse, of other Bodies, (which are external Agents) to perform divers of its Operations, and exhibit several Phaenomena’s, that belong to it.”¹⁵ The qualities of physical bodies, he explained in The Origin of Forms and Qualities (1666), have a “relative nature,” proceeding from the insertion of any single body within the complex whole of the universe. The universe is a vast network of “locks and keys” fitted one to another in such a way that any one part can act upon, and can be acted upon by, the other parts. The qualities stand for these actions and are not themselves real entities; against Aristotelian scholastic philosophy, Boyle argues that qualities are no more than expressions of relations.¹⁶ Similarly, in Cosmical Qualities (1671), he writes: “the Qualities of particular Bodies . . . do for the most part consist in Relations, upon whose account one Body is fitted to act upon others, or disposed to be acted on by them, and receive Impressions from them.”¹⁷

Locke closely echoes Boyle’s picture of the world as a grand system of relations, similarly embraced as a “probable” doctrine. Locke’s aim here is to argue that we can have only imperfect ideas of substances, since the qualities we gather in our complex ideas of them depend on multifaceted relations and concatenations of causes that, by their vastness and complexity alone, are bound to remain, in their entirety, unknown. The parts of the “stupendious Structure” of the universe “may, for ought we know, have such a connexion and dependence in their Influences and Operations one upon another, that, perhaps, Things in this our Mansion, would put on quite another face, and cease to be what they are, if some one of the Stars, or great Bodies incomprehensibly remote from us, should cease to be, or move as it does.”¹⁸ For instance, if a piece of gold were artificially separated from its surroundings, the qualities of color, weight, even perhaps malleability would no longer be manifested; water, if similarly isolated, would no longer exhibit what appears to be its defining quality, fluidity; so with vegetables and animals, we need to see that what we take to be their intrinsic qualities (such as life or motion) depend to a large extent on causes and qualities of other bodies.¹⁹

One lesson that Boyle and Locke draw from this (probable) picture of the world has to do with the limits of our cognitive powers: the extent and complexity of the web of relations in the cosmic structure exceed by far the human capacity of comprehension. For Locke, this is indeed the context of his discussion of the system of the universe: our ideas of substances and real essences are imperfect, and the realization should make us aware of the fact that “we are so far from being admitted into the Secrets of Nature, that we scarce so much as ever approach the first entrance towards them.”²⁰ His repeated claim in the Essay is that natural philosophy cannot hope to become a scientia (or demonstrative science). Not only does the complexity of the interrelations in the universal system exceed our comprehension, but we have no way of deciding on the necessary status of such relations. The corpuscularian hypothesis is, indeed, highly intelligible, yet it cannot discover “what Qualities and Powers of Bodies have a necessary Connexion or Repugnancy one with another.”²¹ This passage is shortly followed by a reference to “the Endowments and Perfections of Cherubims, and Seraphims, and infinite sorts of Spirits above us,” which is meant, here as in a number of other places, to mark a sharp contrast between man’s limited faculties and the “endowments” of the higher spirits, which possibly allow them precisely the kind of knowledge of essences denied to man.²² Thus, not only does Locke maintain an (unreachable) ideal of a demonstrative science of bodies, but he extracts this science from its abstract realm and relocates it, so to speak, in his chain-of-being ontology: a science of bodies is not simply an ideal tout court but a kind of knowledge ascribed to a specific position on the scale of intelligences.

Boyle also associates the picture of the great automaton with a lesson about human ignorance, and he, too, draws the comparison with the capacities of the angels: in his Usefulness, he warns that although the corpuscles’ size, figure, motion, and the qualities resulting from them may be supposed to produce the perceived natural phenomena, yet a naturalist is far from being able to identify and explain the particular causes of a particular effect. Explanation, Boyle warns, is different from, and more difficult to obtain than, intelligibility. Crowning these pieces of warning is an expostulation about the dim powers of the human intellect and the vanity of those who suppose that the “immense Wisdom” of the “Author of the Universe” should, “in his Creating of things, have respect to the measure and ease of Humane Understandings, and not rather, if of any, of Angelical Intellects.”²³ Boyle never goes the length of Locke’s pessimism about the prospects of natural philosophy and is actually hopeful that advances toward the discovery of the “essences” are possible. But like Locke, Boyle emphasizes man’s limited powers, much more impotent than those of the superior intelligences, and infinitely so compared with God’s wisdom. Man’s dim intellect is disproportionate to the fecundity of the world.

The disproportion between man’s mind and the world, therefore, is addressed by the two philosophers in the context of their understanding of God’s attribute of wisdom as expressed in the supremely complex architecture of the world. I believe this calls into question the interpretation of Boyle’s views on the limits of reason as uniquely linked to his conception of divine power and freedom of will, attributed to his “theological voluntarism.” In the words of Margaret Osler, Boyle’s “insistence that God’s will is not constrained by anything in the creation was his fundamental explanation for the limits of human knowledge.”²⁴ Jan Wojcik and John Henry also comment on the link between Boyle’s views about the limits of reason and his theological voluntarism.²⁵ The theological voluntarist emphasizes on the exercise of divine power in the creation of the world counters the rationalist’s insistence on creation according to (the dictates of) reason, which from the perspective of the former threatens to limit, or impose constraints on, divine omnipotence. According to the voluntarism-and-science thesis, a view about the dependency of the world on God’s will, coupled with nominalism and empiricism as the appropriate epistemological and methodological positions, is consequent upon this emphasis on divine power. Another consequence would be a view about the limited nature of human reason. Whether this cluster of themes obeys an internal logical coherence, or was circumstantially brought together for polemical purposes in various debates, has been the subject of an interesting recent exchange between John Henry and Peter Harrison, following the latter’s expression of doubts as to the validity of the voluntarism-and-science thesis.²⁶ The various aspects of this thesis are indeed complex and, I suppose, in need of further clarification. What interests my argument here is that the contexts of the theme of disproportion (and implicitly of the limits of human reason) are not confined to an invocation of divine power. On the contrary, where the idea of the exquisite “cosmic mechanism” is prominent, it is God’s wisdom (often seen as accompanying his power) that serves as the term of comparison for the human cognitive capacities. Thus, for instance, in the context of explaining his notion of nature as a great “oeconomy,” Boyle talks of God’s complete freedom in creating the world while at the same time underlining the supreme rationality (wisdom) of the act: “I suppose no other Efficient of the Universe, but God himself, whose Almighty Power, still accompanied with his Infinite Wisdom, did at first Frame the Corporeal World, according to the Divine Idea’s, which he had, as well most freely, as most wisely, determin’d to conform them to.”²⁷ Both the creation and the preservation of the world are the outcome of a collaboration of power (or freedom) and wisdom. God is indeed the only true “efficient” in the world, since it is through his concourse that the laws of nature and the oeconomy of the universe are preserved.²⁸ On the other hand, the lawlike order of the great system of the world is in fact in keeping with (the dictates of) reason, which is to say, of divine, rather than human, reason: God, Boyle warns in his Usefulness, cannot be supposed to have created the world proportionate to our understanding, but rather “according to the Dictates of his own immense Wisdom.”²⁹

The theme of disproportion does not seem to depend on an emphasis on the divine will. It is rather when measured up against divine wisdom (as expressed in the exquisite “contrivances” of the world—which indeed also testify to God’s power of creation) that man’s capacities of cognitive penetration appear puny. The discussion serves to emphasize (for Boyle as for Locke, and in fact more radically for the latter) the inscrutability, to the eye of man, of a large part of that wisdom. But it is also a token of divine wisdom and goodness, they argue, that there is also some measure of proportion or match between world and mind. In the Excellency of Theology, Boyle says that the obligation to study the truths of God is founded upon the two divine creative acts, “having as well made the World, as given Man the Faculties whereby he is enabled to contemplate it” (emphasis mine).³⁰ In the Usefulness, quoting Seneca, Boyle declares himself nature’s “Admirer and Adorer” and is confident that “Nature hath designed me to act, and imploy my self in Contemplation” (emphasis mine).³¹ Similarly, in the Christian Virtuoso, he reaffirms the divinely designed match between mind and world, with reference to the obligation to discover God’s attributes in creation: “God has given him a Rational Mind, and endow’d it with an Intellect, whereby he can Contemplate the Works of Nature, and by them acquire a Conviction of the Existence, and divers Attributes, of their supremely perfect Author” (emphases mine).³² In the Christian Virtuoso, part 2, the duty to love God equally rests on the (partial) match between the way world and man are made: The world is a grand system infused with harmony and beauty, as expressive of divine wisdom, power, beneficence, and sovereignty. In themselves, Boyle adds, these are “attractive excellencies.” In his turn, man is endowed not only with “natural propensions” toward loving God, but also with reason, a fit instrument for “discern[ing] enough of the divine perfections.”³³ The human faculties are so framed as to be able to discern at least some of the wisdom expressed in creation: this is what grounds man’s duty to engage in the study of it. Moreover, Boyle writes in his Disquisition about Final Causes (1688), it is probable that one of God’s purposes in creation has been precisely to display such fecund wisdom so that it can be contemplated and admired by man: it is “very Likely, that God Design’d, by the great Variety of His Works, to Display to their Intelligent Considerers, the Faecundity (if I may so speak) of His Wisdom.”³⁴

Locke expresses similar views in his treatment of the discovery of the law of nature by man in his Essays of the Law of Nature (written in the early 1660s). The discovery of a lawmaker, of his will and of his wisdom, is the result of a conjoined inspection of world and of man. Both the excellencies of the created world and man’s obvious endowment for knowledge and action argue toward the existence of a will on the part of the creator, expressed in the ends of both world and man. The content of the will, which is also the content of the law, is spelled out, at least at a general level, by the very makeup of world and man. As creation of a “most perfect and wise maker” bearing the mark of a “gracious divine purpose,” all things seem to point to their being “intended by Him to no other end than His own glory.” Equally, the ends divinely intended for man may be grasped by inspection of man’s constitution and faculties, with which he was endowed by the Creator: man finds in himself the faculties of sense experience and reason, the only faculties, Locke says, that can “teach and educate the minds of men” and thus govern the labor of knowledge, so that “things otherwise wholly unknown and hidden in darkness should be able to come before the mind and be known and as it were looked into.”³⁵ The human faculties are for Locke, as for Boyle, educational tools allotted to man as a “stranger” to the divine truths of the world, and it is on realizing their function that he comes to “feel himself disposed and ready to contemplate God’s works and that wisdom and power of His which they display, and thereupon to assign and render praise, honour, and glory most worthy of so great and so beneficient a creator” (emphases mine)—which is the highest end, and so duty, of man, by the side of his duties to other human beings and to himself.³⁶

In a journal fragment of 1677 Locke summarizes these ideas. The mind is not “suited to the whole extent of things”; but there is a fit between the constitution of our nature and the purposes for which we have been created (“to be happy in this world . .. and in the other world”).³⁷ All the knowledge we need is composed of “the history and observation of the effect and operation of natural bodies within our power, and of our duty in the management of our own actions, as far as they depend on our will, i.e. as far as they are in our power,” that is, of “experimental natural philosophy” and “morality and religion.” It is a sign of God’s “greatness” that the world exceeds our penetration, which is apt to “fill us with admiration of his power and wisdom.” But it is also a sign of his “goodness” that the things of nature are suited to our use and that by contemplating them we can “praise his bounty.”³⁸ The Essay is equally suffused with references to the fitness of man’s faculties for the purposes intended for him by the Creator: the “Portion and Degree of Knowledge” allotted to us are enough to ensure the conveniences of this life and the preparation for the life to come.³⁹ The fitness of the faculties for these purposes is in fact one argument against the existence of innate ideas (the faculties’ capacity for learning makes the latter unnecessary).⁴⁰ There is thus, for both Boyle and Locke, not only disproportion but also a divinely designed match between the human mind and the world.

The twofold understanding of the relation between mind and world in terms of both a match and a disproportion is at the basis of these philosophers’ conception of the rightful inquiry into nature and generally into all of God’s “contrivances.” The balance it seeks to strike may be better grasped if compared with the positions on the topic expressed in Pascal’s quarrel with the Jesuits. The Jesuit notion of an unproblematic fitness between human cognitive abilities and nature, resulting in both certain knowledge of nature and ascent of the mind in its meditation upon it, attracted Pascal’s ire. From his point of view, such a position rested on an anthropological fallacy and resulted in anthropological hubris: to fail to recognize man’s postlapsarian disproportion is to commit (once again) the sin of pride. The right attitude in front of this human situation is humility, and the contemplation of nature is valuable not in that it makes man godlike but in that it leads him to recognize his impotency. It should thus be part of man’s effort of realizing that he is an incomprehensible “monster” that only the Gospel can render intelligible and heal.⁴¹

The view held by Boyle and Locke is consistent with the Augustinian-Socratic anthropology I described in chapter 2. If Jesuit-scholastic “proportioning” is untenable, neither is radical disproportion a just representation of human nature. The recognition of disproportion (as well as of the distempers of the human mind) is critical to the self-knowledge that makes possible not only due humility but also the husbandry of the soul and the legitimate advancement of knowledge. Boyle represents the latter in terms of the attitude of the rightful inquirer, who understands aright the balance of proportion and disproportion in his relation to the created world. In the Christian Virtuoso, part 2, he tells us that the inquirer who has begun to cultivate the attention, flexibility, and docility requisite for a “well-disposed mind” in natural investigations is apt to penetrate the “more intimate nature, or constitution of particular things,” and thus to grasp “the exquisite structures and contrivances” (the relations of influence, dependence, coordination, subordination, mutual subservience, harmony, and symmetry obtaining between the parts) of the “cosmical system.”⁴² But that grasp is readily recognized by the same kind of inquirer as only partial: it is due to his understanding of the relational nature of things, and thus of the dependence of any part on the (only partially unfolded) harmony and “cosmicity” of the whole, that he also acknowledges that there are still regions he has not yet, and some that perhaps he never will, penetrate. The growth of knowledge is, therefore, at the same time a growth of an understanding of the limits of knowledge. It is also a growth of “wonder,” as well as the stimulus for praise. With a phrase that recalls the Cusanian vocabulary, Boyle refers to this scenario of knowledge as “learned ignorance”: in contrast to “simple ignorance,” due to neglect of study, and breeding the “admiration of the ignorant,” learned ignorance is the fruit of a growth of knowledge that alone may measure up the territory of the incomprehensible and as such grounds the “admiration of the learned.”⁴³

The full and simultaneous view of “the whole aggregate” of created things, “both singly and in their connection, dependency, and (in a word) their entire system,” Boyle says in the Appendix to the Christian Virtuoso, is reserved to divine omniscience alone.⁴⁴ Man can only discover chains of the system piece by piece, as if he unrolled a “well contriv’d Romance” or a “fine and large piece of tapestry.”⁴⁵ Equally, the “infinitely perfect nature of God” is, from God’s own perspective, comprised in a single idea, with the attributes seen as one rather than itemized. From our limited perspective, though, the divine attributes, just like the parts of nature, can be seen only one by one (“contemplating him sometimes as omnipotent, and sometimes as wise, and sometimes as just, &c.”).⁴⁶ Boyle seems to suggest a parallel between the (fecund) system of the world and the (in reality simple) “system” of the divine attributes. Both transcend the human capacities of comprehension, but at the same time both have a double function: to signal human limitations (to those apt to acknowledge them) and to urge further search (again, to those capable of pursuing it). The effect of the understanding of disproportion is thus the continuation of the search whereby the divine systems of the created world and of the Creator’s attributes may be progressively (although never completely) understood and admired. At times, Boyle seems to think that man has been endowed not only with the cognitive powers requisite for the task but also with a specific form of desire, one that prompts the inquirer never to cease his search: the desire that in Usefulness he calls, quoting Seneca’s Natural Questions, “a desire of knowing the rest.”⁴⁷ The disproportion is thus, in fact, part of the match.

Locke’s picture of the appropriateness of disproportion places much more emphasis on the consequences of the limits of the human intellect, although he, too, advances the idea of a “learned ignorance” that comes with the effort of understanding. On the one hand, understanding the balance of proportion and disproportion in the relation between the human mind and the created world is as crucial to his view of the right conduct of the intellect in natural inquiry as it was for Boyle’s. His discussion of the great system of the world in which parts “owe [their] Being” to their neighbors leads him to the same conclusion that Boyle expanded on: the realization of the systemic nature of the universe and of the interdependence of its parts—which does not come naturally, but requires patient and attentive observation—prompts the continuation of the investigation along the chains of the great system: “and we must not confine our thoughts within the surface of any body, but look a great deal farther, to comprehend perfectly those Qualities that are in it.”⁴⁸ On the other hand, Locke’s emphasis here, as everywhere in the Essay, is on the very need of recognizing aright the wisdom of the disproportion. At some point in his discussion of our ideas of substances in book II of the Essay, Locke invites his readers to imagine what it would be like to have exalted faculties of perception: with enhanced hearing, we would live in a perpetual noise that would make it impossible for us to meditate and even to think. Similarly, with enhanced seeing (or “microscopic eyes”), we would perhaps come to discover the “Texture and Motion of the minute Parts of corporeal things,” and thus their “internal Constitutions” and “secret Composition” (that is, possibly, the things that would make natural philosophy a certain science), but we would also become unable to endure the bright sunshine, and even perhaps the light of day. We would have magnified vision of parts but at the expense of wholes, and, owing to the radical incongruity to other human beings such vision would entail, we would no longer be able to communicate with other people. We would live “in a quite different World.”⁴⁹ The monstrous picture of what a modified human being would be like if equipped for scientia is meant to underline, by contrast, the ordained appropriateness of the human station; the relation between man and world is one of the wise proportions of the divine harmony: “He [God] hath fitted us for the Neighbourhood of the Bodies, that surround us, and we have to do with.”⁵⁰ Our faculties are well enough framed for us to manage our life, and to recognize and admire our Creator. As for the degree of knowledge we are designed to have of the natural world, Locke sounds a powerful cautionary note: some advances in penetrating the nature of bodies are possible, yet only within the epistemic domain of the probable; we are on a surer footing in “improving our Knowledge in Substances only by Experience and History.” Beyond that, it is very likely that “natural Philosophy is not capable of being made a Science.”⁵¹

In what follows I would like to develop the argument that Boyle’s and Locke’s methodological prescriptions for the experimental study of nature, as well as their physico-theology, are informed by this foundational conception of the appropriateness of disproportion between the human mind and the created world. Crucial to this view, I have already intimated, is a concern with the good management of the intellectual and affective capacities of man: the relation between mind and world is not static but involves a process of growth.

Experience, history, and speculation

The justification of an always resumed experimental search in terms of the appropriateness of disproportion is frequent in Boyle’s texts. It is through “particular Enquiries” into the qualities of bodies that a “knowing Naturalist,” as opposed to a “superficial Observer,” becomes able to “discern their secret Correspondencies and Alliances.”⁵² On the other hand, due to the supreme fecundity of divine wisdom expressed in the construction of the universe, Boyle concludes on the mind’s necessarily imperfect grasp of it at any moment of the investigation. The laws of nature are “so various and so numberlesse” and the creatures are so “pregnant” that a full account of the “Properties and Uses” of natural things cannot be expected to be arrived at in a single lifetime.⁵³ The magnitude of the task is no cause for despair, though, but rather points to the need of continued inquiry. Since “there is such a Relation betwixt Natural Bodies,” any new experimental finding should be taken to indicate directions for further search rather than to establish a truth: the inquirer “must not presently think, that he has discover’d a new Truth, or detected an old Error.” The role of experiments is to “suggest new doubts” and to “present new Phaenomena,” and thus to spur a continued search into the universal system of relations.⁵⁴

The requirement of a continued search into particular phenomena governs Boyle’s views on the interplay of theory and experimental and natural history in the legitimate study of nature, as well as on the probable status of findings. The same holds for Locke, although he was more distrustful of theorizing in natural inquiry than Boyle. Nevertheless, I want to show that their views converge on the question of the pernicious effects of “speculation,” in a manner that is congruent with Bacon’s and the virtuosi’s approach to the topic, and thus that their methodologies are partly to be seen as forms of a discipline for the mind.

Recent scholarship has illuminated the strong Baconian inheritance self-consciously assumed by the two philosophers, albeit with variations. In the “Proemial Essay” prefacing his Certain Physiological Essays (1661), for instance, Boyle announces that his project was designed “in order to a Continuation of the Lord Verulam’s Sylva Sylvarum, or Natural History.”⁵⁵ The need for a better constructed experimental history of qualities is also stated in the preface to the Origin of Forms and Qualities, and supported by an invocation of “our Illustrious Verulam.”⁵⁶ Locke, too, as Peter Anstey has documented, was familiar with Bacon’s Sylva in the early 1660s, at a time when he also became associated with Boyle’s programs for exploring the histories of the air and of the human blood, in which he was active until after the end of Boyle’s life, when he edited the latter’s General History of the Air (1692).⁵⁷ In the “Advertisement” to that work, Locke reemphasized the Baconian nature of Boyle’s program.⁵⁸

The extent to which Boyle’s experimental methodology incorporated Baconian principles was signaled by Rose-Mary Sargent in the mid-1980s and has been more recently explored in comprehensive detail in the work of Peter Anstey and Michael Hunter. The latter have highlighted the importance in this sense of Boyle’s letter to Henry Oldenburg of 13 June 1666, in which he presents an “account of my Designe about Natural History.”⁵⁹ The crucial role natural history has for Boyle is also made clear in his prime speculative work, the Origin of Forms and Qualities. The work is aimed, Boyle says, partly at “exciting” his “Learned Friends” to find better explanations for natural phenomena and partly at prompting them to take up the task of collecting histories of qualities, which would be capable of grounding better theories.⁶⁰ The collaborative, ongoing nature of the process of compiling natural histories is repeatedly asserted and enacted by Boyle not only in his experimental activity but also in his literary techniques: a good example of the latter is the unmethodized format of the published History of Human Blood (1684) and his immediately resumed work toward a second edition, which Harriet Knight and Michael Hunter have commented upon.⁶¹ Boyle made the point several times in his writings that he regarded the writing method of “loose tracts” or of “essays” more appropriate for the end of the stimulation of inquiry than the “systematical” manner, thus echoing Bacon’s and the virtuosi’s critique of the barrenness of beautifully methodical and closed systems.⁶² The “testimonies” of nature to be collected in natural and experimental histories are distributed between what Bacon described as nature in its ordinary course, and nature “vexed” by art, or “Cited to make her Depositions by the Industry of Man.”⁶³ The requirement of considering nature “vexed” by art in the compilation of the history, and the organization of what Bacon called “articles of inquiry” in the manner of “heads” or “titles,” are principles which Boyle took over from Bacon or the Baconian program of the Royal Society, while also adapting and elaborating on them.⁶⁴

Moreover, as Anstey and Hunter comment, it is within the context of designing guidelines for constructing natural histories that Boyle reflects on the reciprocal relation between constructing natural experimental histories and formulating theories and hypotheses. The natural history, Boyle writes in his “Designe,” should neither ignore existing “hypotheses” (explanatory doctrines) nor be “confin’d to any.” It will in fact be able to “amplify & correct” existing theories, while at the same time using theories with a view to producing better framed experiments and to better understanding previous errors. The overall aim is not to test and verify theories but rather to “produce new Phaenomena” and to use theories in order to “make the History both more exact and compleat in it self, and more ready for use, and more acceptable to those that love to discourse upon Hypotheses.”⁶⁵ Against the hypothetico-deductive interpretation of Boyle’s method, Anstey and Hunter conclude that what he envisages is a “two-way reciprocal enterprise in which theory informs experiment with a view to constructing a natural history, which in turn informs theory.”⁶⁶ Sargent argued for a similar interpretation, stressing the correct way in which to understand Boyle’s warning about the “probable” nature of theoretical conclusions: “the conjectural nature of the inferences resulted from the absence of complete natural histories, not from the in-principle conjectural nature of science.”⁶⁷

Boyle did have a positive view of hypotheses, and he reflected on what a “good hypothesis” should consist in: it would have to be intelligible and free from any impossible, false, or absurd propositions, and it would have to be self-coherent and consistent with the phenomena it purports to explain, as well as with all the other known phenomena. In order to be “excellent,” it would have in addition to be the simplest and the only one that best explicates the phenomena, and it would have to have predictive power.⁶⁸ These were indeed the qualities that for him recommended his own corpuscularian hypothesis.⁶⁹ But explanations in terms of the ultimate “affections of matter” were neither possible nor desirable in every case under consideration, Boyle warned, so that second-order explanations in terms of “subordinate Causes” were called for.⁷⁰ In all these cases, in which reason took up the role of the rightful judge of experience,⁷¹ the construction of hypotheses was legitimate in that they could point the way to the discovery or production of “new phenomena.” Reasoning and interpretation of experimental data were not only useful but inescapable and took the form of a “trial” on the model of the juror or of the “refiner” of metals. But such judgments, Boyle warned, can be only probable, or “morally certain” at best.⁷² Hypotheses must be built on a sufficient basis of natural history, and this is so difficult to obtain that extreme caution should be manifested in “erect[ing] such Theories as are capable to explicate all the Phaenomena of Nature.” Thus, the strong requirement Boyle makes is that such “superstructures” be held “only as temporary ones”: they are “not entirely to be acquiesced in, as absolutely perfect, or uncapable of improving Alterations.”⁷³ They have therefore the status of the “probationary” dictates of reason I discussed in chapter 4. This is a status, it should be noted, that hypotheses share with the “topics of inquiry” around which a natural history should be organized, as Boyle writes in his “Designe”: these topics, especially in the first stage of inquiry, cannot be “compleat & consequently are not to be stable & fix’d <but> if I may call them Probationary and so to be alter’d &c. according as further Discoverys or more mature Consideration shall enable and invite to change & inlarge the particular Topicks.”⁷⁴ There is thus a similar epistemological status Boyle reserves for (theoretical) hypotheses and (natural historical) topics of inquiry: both are probable and temporary. They also fulfill a similar methodological role in that they help direct and expand the investigation of particulars. In this way, Boyle echoes the Baconian notion of the tight relations among natural history, literate experience, and the collection and analysis of prerogative instances, coupled with the requirements that they be used to direct further inquiry, that results at every stage be assigned progressive degrees of certainty, and that they be held as only temporary.

Locke’s view of the legitimate method of natural investigations is also firmly entrenched in an appreciation of the value of natural history. The difference from Boyle’s conception lies in his much more skeptical position relative to the use of hypotheses. Building on John Yolton’s insight in his 1970 study on Locke, Peter Anstey has augmented the case for a Lockean natural historical method, against the hypothetico-deductive interpretation that was dominant from the 1960s to the 1980s, in Locke’s as in Boyle’s case.⁷⁵ The general stance here, premised on Locke’s denial of epistemic access to the real essences of bodies, is summarized by Yolton thus: “far from Locke’s denial of any knowledge of real essence leading to conjectures about real essence, that denial leads him to locate the science of nature with observation and experience.”⁷⁶ A number of powerful arguments support the Yolton-Anstey thesis. First, among the types of agreement of ideas that Locke says knowledge consists in, the only one pertaining to substances is that of “co-existence,” where “coexistence” is to be contrasted with “necessary connection”: the coexistence of qualities can be known with certainty, although this is not the general knowledge that insight into the necessary connections of qualities would afford. Thus, Locke allows for a sensitive and experimental type of knowledge (a particular, not a general type), based on collections of qualities observed to coexist.⁷⁷ Second, hypotheses, as a species of probable thinking, are thus emphatically not conducive to knowledge for Locke, but are only probable. They are generally dismissed as nonscientific, in the strong sense of the word “science.” Rather, hypothesizing is generally speaking a potentially dangerous activity, since it easily leads to the embracing of an unwarranted “principle”—a form of “dogmatism.”⁷⁸ Third, when Locke does speak favorably of hypotheses, he does so only briefly, as a sort of concession. But what he has to say about the legitimate use of hypotheses still does not amount to any hypothetico-deductive method in any recognizable sense, since their role is to advance and guide experience itself, or the collection of histories, by helping the inquirer to discover and range new phenomena. Rather than being “foundations of reasoning” relative to which the observed phenomena would play an evidentiary role, “hypotheses and analogical reasoning find their domain of application in the compilation of natural histories.”⁷⁹

Indeed, Locke warns in several places that we should “adapt our methods of Enquiry to the nature of the Ideas we examine,”⁸⁰ and if we do that, as Reason itself advises, we will recognize that while, for instance, morality may be capable of demonstration, in the case of “substantial Beings,” “Experience here must teach me, what Reason cannot.” Experience is the adequate method in the case of the “co-existence” of ideas: we may know, for instance, by repeated experiments, whether any additional quality may be added to our complex idea of a thing, e.g., whether malleability should be included in our complex idea of gold, by the side of its being yellow, heavy, and fusible.⁸¹ It is only such particular knowledge that may form the domain of experimental natural philosophy, which should be approached by “this way of getting, and improving our Knowledge in Substances only by Experience and History.” Locke adds, significantly for the anthropological rooting of his methodological views, that this “is all that the weakness of our Faculties in this State of Mediocrity, which we are in this World, can attain to.”⁸²

One example of Locke’s critical use of “hypothesis” is in his discussion of cohesion. We do perceive the extension of bodies, which is “nothing but the cohesion of solid parts,” yet the various hypotheses advanced for explaining the causes of cohesion (e.g., the pressure of the air, or of a subtler matter such as the ether, holding the sensible parts of bodies together) are to be recognized as impotent (they would not explain how it is that the particles of air or of ether themselves hold together). Although ingenious, such hypotheses ultimately “leave us in the dark,” and the essential nature of cohesion, just like the nature of thinking, remains incomprehensible to us.⁸³ To expect full clarification here is as transgressive as to do so in relation to the question whether consciousness is the “affection” of one individual immaterial substance or not. Locke decides to “let Men according to their divers Hypotheses resolve of that as they please,”⁸⁴ since the experience of consciousness, which anyone can testify to, is enough for resolving questions of personal identity, just as the experience of cohesion is enough for studying the behavior of bodies, without our having to decide on a particular explanation of the nature of either matter or spirit.

Another example is Locke’s criticism of “maxims.” Consider, Locke proposes, the several ideas of body held by different philosophers: whichever idea one may fix on (be it “extension” alone, or “extension and solidity”), demonstrations as to the nonexistence or existence of vacuum will easily follow in both cases, with no possibility of refuting one by the other.⁸⁵ This way of approaching bodies by verbal proposition, Locke concludes, is totally futile, and “they cannot discover or prove to us the least Knowledge of the Nature of Substances, as they are found and exist without us, any farther than grounded on Experience.”⁸⁶ Even more pernicious is the unexamined taking up of principles on which to found a whole philosophy, not just of nature, but of morality, too: from a blindly embraced principle like “all is Matter” there derive both bad philosophy and a vicious conduct of our lives.⁸⁷ Locke concludes: neither “general Maxims,” nor “precarious Principles,” nor “Hypotheses laid down at Pleasure” can serve the inquiries of a truly rational creature.⁸⁸

Even though Locke downplayed theorizing in natural historical inquiry, while Boyle recognized its advantages, the two philosophers were in accord on the question of the harmful effects of system building, or “speculation,” both for the legitimate method and for the good conduct of the mind in natural inquiry. (As a matter of fact, it is in this sense that Locke most often uses the term “hypothesis.”) This is again a Baconian theme, present both in Bacon’s and in the virtuosi’s writings, but that may also be fruitfully seen, I have suggested, in the context of the cultura animi type of defense of “useful” against “speculative” knowledge. The latter is criticized as “barren,” not only in the sense of not being conducive to “works,” but also in terms of its unfruitfulness relative to the right conduct of the mind in inquiry. The Baconian analysis of speculation in terms of the operations of the distempered mind, involving irregular assent, the narrowing effect of the tincture of beloved opinions, and the self-adoring stance, had as a counterpart the framing of experimental inquiry as an exercise apt to govern the “agitation of wit” responsible for the speculative inclination, and to cultivate the “universality” and the humility capable of mastering and orienting the mind of the inquirer. I have shown that this theme is taken up and elaborated by the virtuosi in their methodological and apologetic writings. Here I would like to claim that Boyle and Locke echo the same vision, and thus that their defense of experimental against speculative philosophy is similarly founded on their conception of the distempers and regimens of the mind that I explored in chapters 4 and 5. The natural-historical interpretation of their methodology, as well as the theme of the Baconianism of later seventeenth-century experimental philosophy, will be enriched, I hope, by recognizing the theme of the education of the inquirer.

Two main themes are relevant here. First, speculation is associated with one frequently rehearsed item in the lists of weaknesses and defects of the mind that both Boyle and Locke shared with the anatomies of the mind I have investigated: the “forwardness” or “haste” of the mind in inquiry. Boyle warns that the inquirers should avoid formulating too general theories on the basis of too scant a collection of, or of too poorly examined, phenomena. They are thus “to set themselves diligently and industriously to make Experiments and collect Observations, without being over-forward to establish Principles and Axioms.”⁸⁹ The very construction of philosophical systems is due to “mens forwardness to write entire bodies of Philosophy.”⁹⁰ Here “our great Verulam” showed the way in his effort “to restore the more modest and useful way practis’d by the Antients, of Inquiring into particular Bodies, without hastening to make Systems.”⁹¹ Moreover, debilitating “haste” should be avoided not only in the inquiry into the “relations” of the cosmic mechanism but also into the “ends” or final causes it exhibits. The ends form an equally complex structure as the relations do (e.g., “animal ends” are integrated with the “cosmic ends”): we should thus not be “Over-hasty in concluding” that this is an end or that a divine motive.⁹²

Similarly, for Locke, general hypotheses are often the result of the same flawed movement of the mind, as inventoried in the Conduct: the hastiness or precipitation of the mind, which “must have some Foundation to rest it self upon” and thus unwarily embraces any “hypothesis” that it finds ready to fulfill that function.⁹³ In the Essay, he also writes, in the context of discussing the use of hypotheses at IV.xii.13: “the Mind, that would always penetrate into the Causes of Things, and have Principles to rest on,” is prone to use hastily formed hypotheses as such bedrocks of reasoning.⁹⁴ The notion of an irregular mental movement at play in the framing of speculative hypotheses was firmly present in Locke’s thinking early on, as can be seen in his De Arte Medica (1669): “[Man’s understanding is] very restlesse and unquiet till . .. it has framed to its self some hypothesis and laid a foundation whereon to establish all its reasonings . .. and puting all these phansies togeather fashioned to themselves systems and hypotheses.” This text was written during Locke’s collaboration with Thomas Sydenham, himself a close acquaintance and admirer of Boyle’s. The preface to Sydenham’s major work, Observationes Medicae (1676), includes methodological prescriptions that, as G. G. Meynell has shown, are direct echoes of Locke’s conception of method. Thus, for instance, the practice is decried of those medical writers “whose minds have taken a false colour” (become tinctured) under the influence of a “philosophical hypothesis.”⁹⁵ To keep speculative hypothesizing at bay is therefore, for Locke, not only a methodological prescription, but also a therapeutic requirement. The building of natural histories—of the air, of the human blood, of diseases or of botanical specimens⁹⁶ —acquires thus not only the function of a legitimate method but also the value of an exercise for regulating the intemperance of the mind.

Second, speculation is associated with the construction of “systems” that purport to establish definitive interpretations of nature. It is thus, for Boyle, a direct consequence of the lack of recognition of the disproportion between the human mind and the fecund richness of the created world and speaks of man’s reliance on his “abstracted reason.” To devise a system is to block the growth of knowledge, and in view of his association of that growth with an effort of self-mastery, it is also to allow free rein to the “prepossessions” and “corrupt affections” of the mind. In Baconian parlance, it is to fail the perspective of the universe and to fall into pride. What the “speculative Devisers of new Hypotheses” aim is to solve, rather than “increase or apply,” the phenomena; it is thus “no wonder that they have been more ingenious than fruitful.”⁹⁷ The prepossession of the mind, together with an ill-managed assent (the “want of freedom and attention in our speculations”), combine with the “want of a competent history of nature” in the establishment of errors.⁹⁸ In contrast, building experimental histories of nature, directed by carefully devised hypotheses and topics of inquiry, and guided by “docility,” represents a proportionate acknowledgment of the disproportion between mind and world. The probabilism attached to the theoretical moments of natural investigations is best seen as a feature of the “probationary” nature of both hypotheses and topics of inquiry: it presupposes a statement of the type “not yet” (you have not grasped the whole truth yet), which also involves a moral injunction of the type “do not presume that you have reached the end” (thinking so is to remain prisoner to your private view).⁹⁹ In this sense, the discipline of judgment implied in Boyle’s notion of “docility” is a means of always recognizing that the search is not over.

Locke’s strictures on hypotheses in natural inquiry are also primarily strictures on the building of speculative systems. He criticizes the solidification, so to speak, of a hypothesis into a system that acquires by accretion of both time and trust the prestige of uncontested and dogmatic truth. As such it breeds credulity and “implicit faith,” which are exemplars of the types of mind distortion he charted in his Essay and Conduct. Fidelity to one such system becomes thus above all fidelity to a set of terms and to a philosophical sect: “to this Abuse, those Men are most subject, who confine their Thoughts to any one System, and give themselves up into a firm belief of the Perfection of any received Hypothesis.”¹⁰⁰ The work of examination, whetted by a love of truth, which Locke recommended in his Conduct, would thus be the type of practice of the mind apt to keep it safe from the dangers of dogmatic system making or accepting. In his journal of 1677, Locke wrote that “speculations in Nature” are a mark of the failure to acknowledge the areas where knowledge is possible and useful and where it is not, or else the areas of proportion and the areas of disproportion between the human mind and the created world: men “need not perplex themselves about the original frame or constitution of the universe, drawing the great machine into systems of their own contrivance, and building hypotheses, obscure, perplexed, and of no other use but to raise dispute and continual wrangling” (emphasis mine).¹⁰¹ Equally, in his Some Thoughts concerning Education, Locke wrote that “the Works of Nature are contrived by a Wisdom, and operate by ways too far surpassing our Faculties to discover, or Capacities to conceive, for us ever to be able to reduce them into a Science.”¹⁰²

Speculation as Boyle and Locke understand it in these contexts would be the very attempt to “reduce” the wisdom manifested in creation, or the “fecundity” of God’s works, to a human measure. Instead, the proportionate response of the true inquirer is to continue the search and to take care to recognize (dis)proportions. It is also, at the same time, to cultivate admiration and reverence for the Creator: the counterpart of the natural historical method is an exercise of natural religion.

Affective cognition

For Boyle, the experimental study of nature was one way of fulfilling the Christian’s office of rendering praise to God. The striking image that encapsulated this idea for him was that of the naturalist as a “priest” of the “temple” of the world, celebrating divine service (the “sacrifice of praise”) on behalf of the whole creation.¹⁰³ The understanding of natural historical inquiry as a natural theological activity is one facet of the complex early modern relationship between natural philosophy and theology, which shaped the distinct genre that was to be called “physico-theology.”¹⁰⁴ In one sense, the project of physico-theology may be described as the framing of arguments based on the perceived tokens of divine workmanship in the natural world toward the demonstration of God’s existence and providence manifested in creation.¹⁰⁵ According to Peter Harrison, physico-theology thus framed was gradually established as an “inductive science” in the eighteenth century. Devised as a “mixed science” at the crossroads of theology and natural philosophy, it rested on a specific type of explanation, of which Boyle provided the formal account,¹⁰⁶ and in which natural histories functioned as “a logical premise from which God’s wisdom and providence could be inferred.”¹⁰⁷ But this representation of physico-theology in terms of explanatory strategies serving a logical demonstration misses an important aspect of Boyle’s view of physico-theological reasoning, which answers his framing of experimental investigations as a “sacrifice of praise.” His talk of “arguments” in this context seems to point to the unfolding of an exercise for the mind rather than (simply) of a demonstration, where the study of the creatures functions more like an experiential premise, followed by advances in both understanding and emotional capacities, rather than by steps in a logical argument. The end point of such reasoning, for Boyle, is not only the demonstration of the existence of God (against the “atheist”) but also the building of a religious virtuous disposition in the devout philosopher.

Thus, in his Final Causes, where the term “physico-theological reasoning” is employed, Boyle distinguishes between two types of reasoning from ends: physico-theological (which, from perceived uses of things, argues toward the existence of an Author and his general ends in creation) and physical (which, from those supposed ends, argues toward the nature of the corporeal things).¹⁰⁸ The former is most aptly applied to the “Universal Ends” of creation, which refer to “the Exercising and Displaying the Creators immense Power and admirable Wisdom, the Communication of his Goodness, and the Admiration and Thanks due to him from His Intelligent Creatures.”¹⁰⁹ Physico-theological reasoning is legitimate primarily in that it inspires devotion and piety. God’s existence, providence, and attributes are, in Boyle’s words, “manifested” by the physico-theological reasoning, where the “manifesting” is more effective than the mere “showing” performed by the Cartesian ontological proof.¹¹⁰ The Christian inquirer is not only to “observe” but to become “Affectively Convinc’d” of the wisdom of God.¹¹¹

Crucial to the theologically informed experimental inquiry into nature is not simply the demonstration of the existence of God (in the manner of the classic argument from design, say) but the offering of praise, and, as Boyle puts it, the “elevation of the mind” through contemplation of sublime objects, which can kindle a superior type of affections. This is not to say that the demonstration of the existence of God forms no part of Boyle’s understanding of the theological role of natural philosophy. That is indeed its first principle, as he says in the Christian Virtuoso. The crucial point is that he formulates that task in terms that ask not primarily for a logical demonstration but rather for a working up of belief in a manner that is both rational and affective.

In the Christian Virtuoso, part 2, Boyle calls this type of belief “philosophical faith” and characterizes it in terms of degrees of assent. Philosophical faith varies with the degree of firmness of the “assent that, upon the grounds furnished by nature, men have concerning the existence and chief attributes of God.” There may be “a very weak assent,” which, although guarding man from atheism, will not be enough to make him pious. On the contrary, “his piety, as well as his other virtues, will usually be proportionate to the firmness of the assent he gives to that fundamental article of religion, that there is a Divine Maker and Ruler of the world.”¹¹² Such firmness of assent can come only with the careful, deep-looking inquiry into the great fabric of the world that Boyle advocates as the true experimental philosophical task, and with the contemplation of the samples of divine workmanship in the “relations” of the world, which will be as many arguments grounding one’s faith. The point is clear in the Christian Virtuoso, where the weak versus firm assent distinction is echoed by the “ordinary swimmer” versus ”skilful diver” contrast between degrees of attention. “Perfunctory Considerers” look swiftly only at the surface of things and thus can form only (weak) “assent,” while the “Heedful and Intelligent Contemplator” discovers the illustrations of divine artifice in the “recesses” of nature by means of a detailed and discriminating investigation of particulars, allows them to sink in, and is thus capable of forming a (strong) “belief” in the existence of the Creator.¹¹³ The chief example of a weak assent-forming argument is that of the scholastics: their accounts of nature are dispensed with in a few words, and the examples they use are too general to be effective. As such, they do not urge man to search more into the “structures of things” and by themselves are insufficient to reveal the “exquisite Wisdom” that the Creator expressed in the makeup, motion, and functioning of natural bodies.¹¹⁴ In other words, they remain logical arguments, without managing to become experiential arguments. The latter depend precisely on the patient unraveling of the relations of particulars in the fabric of the world, which we have seen was the legitimate mode of inquiry premised on the appropriateness of disproportion.

But the strong belief in question is not the result of a uniquely cognitive process. Boyle rather talks of a way of affecting the mind so as to form a special sort of belief, a “conviction” that is both rational and affective. The experimentalist is not only able to say that God is wise but discovers more and more how wise he is; and with the discovery he is transformed in his understanding and in his emotions: “And ’tis not by a light Survey, but by a diligent and skilful Scrutiny, of the Works of God, that a Man must be, by a Rational and Affective Conviction, engag’d to acknowledge with the Prophet, that the Author of Nature is Wonderful in Counsel, and Excellent in Working” (cf. Isaiah 28:29).¹¹⁵ The hierarchy of observers as dependent on a hierarchy of degrees of attention is present here again, when Boyle distinguishes between a “general, confus’d, and lazy Idea” of God’s power and wisdom and the “distinct, rational, and affective notions of those Attributes which are form’d by an attentive inspection.”¹¹⁶ A mind that becomes prepared for praise is a mind that is being touched in its affections and thus intimately transformed. The language of love, desire, and wonder comes to be inextricably blended with the language of rationality. Boyle calls this cognitive-affectionate state (or rather active disposition) of the mind “rational Wonder.”¹¹⁷ Admiration, celebration, humility, gratitude, love, and trust are Boyle’s examples of what he alternatively calls “the nobler acts of natural religion” or the “religious virtues,” cultivated by the diligent student of nature.¹¹⁸

Furthermore, in his Usefulness Boyle calls the proper study of nature a “concern’d survey” that is propelled by “an inquisitive Industry to Range, Anatomize, and Ransack Nature” and is conducive to an “exquisite Admiration of the Omniscient Author.”¹¹⁹ The meaning of “concern’d” is spelled out in his Excellency. There, in proceeding to show what the “contentments” are “accruing from the study of nature,” Boyle develops a simile comparing the inquirer’s attitude toward “the wonders of Nature” and thus toward God their “wise Author” to the attitude toward “such an one as he intirely honours and loves, and to whom he is related.” The student of nature needs to see himself as a friend, child, or else “passionate Lover” of his object of inquiry: his quest will thus be “concern’d,” and it is by means of such a concerned pursuit that our “inclination to self-love” may be countered and the mind may attain the dynamic quality of rational wonder.¹²⁰

The God that the experimentalist relates to (rather than demonstrates), on Boyle’s view, is a creator and a parent, a preserver and benefactor, as well as a sovereign. To form such a (true) notion of God is the fruit of a long, diligent, docile exercise in the careful observation of the world. The superficial spectator (or the scholastic metaphysician) can go no further than an “undiscerning, weak, or unconcerned” notion, which is “in a word, a mere nominal deity.” In contrast, an experimental relating to God may reveal him as the “powerful, wise, just, and active author, upholder, and sovereign governor of the world,” which is, Boyle adds, also the true philosophical notion of him.¹²¹ The notion of an “active God” is in direct relation with Boyle’s theological ontology of matter moving with the continual concourse of the divinity, as well as with the image of the world as rich and fecund. The “pregnant Automaton” may not be exactly breeding new offspring, but it is itself the fruit of an original fecundity expressive of both wisdom and power, and it is perpetually infused with divine activity. It is apparent from Boyle’s continued reflections on the theme that the experimental search for the truths of nature is conceived as a renewed encounter with that activity, wisdom, and power.

If Locke cannot be expected to display the radiant eloquence that Boyle cultivated early in his writing career and traces of which are visible in his natural theological metaphors, his understanding of the study of nature as an act of devotion is nevertheless close to Boyle’s. A similar conception of the special type of “conviction” about God bred in the student of nature—one that involves the mind’s wonder, attention, and concern, is expected to work up an inner transformation, and is set in opposition with the demonstrative types of proofs for the existence of God—can be identified in his early Essays on the Law of Nature, as well as in the natural theological passages of the Essay. It is significant in this sense that Locke became familiar with Boyle’s Usefulness shortly after its publication, that is, during the period when he was writing the Essays on the Law of Nature, and that he read and commented on a first draft of the Christian Virtuoso in 1681, before the publication of his Essay.¹²²

In the Essays on the Law of Nature Locke elaborates on how sense experience and reason work together for the establishing of truths about natural law and God. But here, as in Boyle, at stake is not demonstration and logical inference but rather a process of growth in awareness and appropriate emotion. The steps Locke describes are at one level steps in an argument, but at the same time they are also experiential steps: what he does is in some sense narrate the story of what happens to a mind that sets itself the task of learning about God from nature. Thus, in a first step, the senses identify the existence of sensible bodies with their attendant qualities, “namely lightness and heaviness, warmth and coldness, colours and the rest of the qualities presented to the senses, which can all in some way be traced back to motion.” By the same movement they discover “that this visible world is constructed with wonderful art and regularity,” as is perceivable in the motion of the stars, the course of the earthly waters, or the succession of seasons. This perceptual grasp of the world by the senses is also reflected back on the perceiver: “and of this world we, the human race, are also a part.”¹²³ The work of the mind as prompted by the senses is one of impressing upon the beholder the structure (“fabric”) and the harmony (“beauty”) of what he sees—a work of what Locke calls “careful consideration” and “contemplation”: “the mind, after more carefully considering in itself the fabric of this world perceived by the senses and after contemplating the beauty of the objects to be observed, their order, array, and motion, thence proceeds to an inquiry into their origin, to find out what was the cause, and who the maker, of such an excellent work.”¹²⁴

The “consideration” and “contemplation” required for the process of the discovery of God and his law in nature are members of the superior degrees of thinking listed in the Essay, on which I commented in chapter 5. I suggested there that “attention” and its cognates are for Locke complex modalities of thought that involve an affectively oriented cognition, guiding the mind and preserving it from the debilitating effects of laziness and precipitation. In the Essays on the Law of Nature, Locke also points out the “great labour” needed if unobvious things or “those resources which lie hidden in darkness are to be brought to the light of day.” He is echoing here the truth-lies-deep notion, which was common currency among Protestant views of the pursuit of knowledge, where the difficulty of knowledge was accompanied by the idea of a need for labor and industry, as opposed to idleness. In the same vein, Locke writes: “they [the resources] do not present themselves to idle and listless people,” but indeed “careful reflection, thought, and attention by the mind is needed, in order that by argument and reasoning one may find a way from perceptible and obvious things into their hidden nature.”¹²⁵ The “attention by the mind” is therefore the requisite mode (and degree) of thought involved in the conjoined work of senses and reason in the discovery of God and his law.

Thus, the discovery of the existence and will of a Creator by inference from the senses is not the result of a casual glance at the things around; it requires a work of the intellect on experiential data, which Locke gradually came to think was a sort of passionate cognition. Nor is that discovery a matter of theoretical demonstration: Locke explicitly repudiates, as did Boyle, the metaphysical or logical proofs for the existence of God, as well as the accounts of the knowledge of the law of nature as based on innate notions, on conscience, and on tradition.¹²⁶ The argument offered by his alternative solution is not only, or not simply, an argument tout court. It does establish a truth and a duty, and requires a careful work of reason that it may succeed. But in doing so, it is also proposed as a form of doing, as a practice of the duty that one finds it establishes. In inferring the existence, power, and wisdom of a God from the works of nature, the mind is already, if attentive, engaged in that “praise, honour, and glory” that man’s duty, as he finds out, demands.

The practical, experiential dimension of this type of knowledge pursuit is repeatedly emphasized in the Essay, where Locke says that it is in fulfillment of our duty, which is at the same time a concern for our souls, that we should order our lives so that we can attain the happiness to be had in this world and prepare for the happiness that awaits the just in the other. The study of nature is emphatically placed in this very context, of the practice of our lives informed by our duty to our Creator. The Essay does of course also present an argument for the existence of God in the manner of a logical demonstration in book IV, chapter x. The argument there seeks to establish the preeminence of thought over matter and thus the fact that matter could not, in and by itself, have created thought. The Essays on the Law of Nature, in contrast, was not primarily concerned with establishing that God is a thinking being. Its aim was to make clear the steps through which the mind could come to the recognition of a deity and of some of its ends in creation—which formed the foundation of the discovery and understanding of the law of nature, or the basis of our lawful conduct in this world. This strand of the account in the Essays on the Law of Nature does not inform the demonstration at Essay IV.x but is instead scattered through the parts of the Essay that discuss the extent of our knowledge of nature. Thus, for instance, in his discussion of the “Improvement of our Knowledge,” Locke exposes again the limits of our knowledge of bodies but adds: “I would not therefore be thought to disesteem, or dissuade the Study of Nature. I readily agree the Contemplation of his [God’s] Works gives us occasion to admire, revere, and glorify their Author.”¹²⁷ Likewise, inserted in his discussion of our ideas of substances, and in the vicinity of a reaffirmation of the limits of man’s faculties, is a fragment that recommends the study of natural things for the two main reasons that it helps with the “Exigencies of this life” and that “we have insight enough into their admirable Contrivances, and wonderful Effects, to admire, and magnify the Wisdom, Power, and Goodness of their Author.”¹²⁸ Locke emphasizes repeatedly that this kind of knowledge—which is accompanied by recognition, wonder, and praise—is the kind suited to our condition and ends.

The rightful business of the human mind, Locke and Boyle agree, is to scrutinize the particulars and their relations in the “system” of the world, which is the bedrock both of rightful natural philosophy and of natural religion. Knowledge of the qualities and powers of bodies is apt to improve the practical, beneficial sciences, such as medicine, botany, or chemistry. It may also, Boyle believed, although Locke was less confident, reveal more and more about the true nature of things and confirm (or disprove) the corpuscularian hypothesis. On the other hand, this type of pursuit of natural knowledge also makes possible the careful contemplation of the structures and ends of the cosmos, and of man’s place in it, which may spell out for him his duty and concern.

The experimental study of nature is also, for both authors, an exercise in understanding proportions, which is indeed an exercise in self-knowledge in the context of the divinely authored universe. There is a match between mind and world, but that match includes a crucial amount of disproportion. A right understanding of the dimensions of this disproportion is of the essence for man’s understanding of his place in creation and for the pursuit of useful knowledge (the knowledge that will improve his mind and life). It also enables the cultivation of the “religious virtues” of admiration and praise of the Creator. The affective cognition generated by what Boyle calls physico-theological reasoning, and Locke the inference to providence, is for these authors the outcome of a transformative exercise that works on the cognitive, moral, and affective powers of the inquirer. It is thus part and parcel of their conception of the education of the human mind, now approached from the perspective of the cultivation of its religious virtues.