SAD HUMOR
The sad humor is composed of slowness and disquiet, and can be augmented by malignity and timidity.
Treatise on Man. XI, 167.
SADNESS
Sadness is a disagreeable languor, which consists in the annoyance that the soul receives from evil, or from some fault, which the impressions of the brain represent to it as pertaining to it. And there is also an intellectual sadness, which is not a passion, but which is almost always accompanied by it.
Passions, II, 92. XI, 397.
In sadness, the pulse is feeble and weak, and something like cords are felt about the heart, which press against it, and ice which freezes it, and communicates its coldness to the rest of the body; and nevertheless one often retains a good appetite, and senses that the stomach still does its job, provided that there is no hate mixed with the sadness.
Passions, II, 100. XI, 403.
Often, after having laughed a great deal, one naturally feels inclined to sadness, because the more fluid part of the blood from the spleen has been exhausted, and the other, thicker blood follows it to the heart.
Passions, II, 126. XI, 421.
See joy.
SALT
Sometimes it happens that the salt which comes from the sea passes through the pores of the earth which are so narrow, or so arranged that they change something in the shape of the particles of salt, by means of which it loses the form of common salt, and takes on that of saltpeter, sal ammoniac, or some other kind of salt.
Principles, IV, 69. IX2, 238.
SATISFACTION
We can also consider the cause of good or evil when it is as much present as past. And the good which has been done by ourselves gives us an internal satisfaction, which is the sweetest of all the passions; on the other hand, evil excites repentance, which is the bitterest.
Passions, II, 63.
The satisfaction, which those who constantly follow the path of virtue always have, is a habit in their soul, which is called tranquility and ease of conscience. But that which is newly acquired, when one has just done some action which he thinks is good, is a passion, namely a species of joy, which I believe to be the sweetest of all, because its cause depends only upon ourselves.
Passions, III, 190. XI, 471.
SCEPTICS
I did not imitate the sceptics, who doubt only for the sake of doubting, and always pretend to be irresolute.
Discourse, III. VI, 29.
SCHOLASTICISM
In case anyone is put out by this new use of the term intuition and of other terms which in the following pages I am similarly compelled to dissever from their current meaning, I here make the general announcement that I pay no attention to the way in which particular terms have of late been employed in the schools, because it would have been difficult to employ the same terminology while my theory was wholly different.
Rules, III. X, 369.
The monks have given birth to all the sects and to all the heresies, by their theology, that is, by their scholasticism, which must be destroyed before anything else.
Burman. V, 176.
SCHOOLS
We very often see that people who have never troubled themselves with study make clearer and more solid judgments than those who have passed their time in the schools.
Rules, IV. X, 371.
SCIENCE
I do not want to give the public another Lullian Ars Brevis, but a science with new foundations, which permits a general resolution of all questions which can be proposed, for any type of quantity, continuous or discontinuous, but each according to its own nature.
To Beeckman, Mar. 26, 1619. X, 156-57.
Science is like a wife; if, modestly, she remains close to her husband, she is honored; if she gives herself to everyone, she cheapens herself.
Cogitationes Privatae. X, 214.
The sciences are now masked; if the masks were removed, they would appear in all their beauty.
Cogitationes Privatae. X, 215.
Determinate limits are prescribed for all minds: they cannot go beyond them. If certain persons, by default of mind, cannot use principles of invention, they will be able at least to know the true price of the sciences; and that will be enough to provide them with true judgments about the value of things.
Cogitationes Privatae. X, 215.
Since the sciences taken all together are identical with human wisdom, which always remains one and the same, however applied to different subjects, and suffers no more differentiation proceeding from them than the light of the sun experiences from the variety of the things which it illuminates, there is no need for minds to be confined at all within limits.
Rules, I. X, 360.
All science is certain and evident knowledge.
Rules, II. X, 362.
One ought to derive the sciences — even the most profoundly hidden ones — not from imposing and obscure principles, but only from principles which are easy and quite close at hand.
Rules, IX. X, 402.
All human science consists of one thing: namely, the distinct vision of the way in which simple natures combine together in the composition of other things.
Rules, XII. X, 427.
The knowledge of the order [of the positions of the stars] is the key and the foundation of the highest and most perfect Science that men can have concerning material things; so much so that by means of this science one could know a priori all the various forms and essences of terrestrial bodies, rather than, without it, being forced to content ourselves with guessing at them a posteriori, and by their effects.
Letter to Mersenne, May 10, 1632. I, 250-251.
By [mathematical] science I understand the ability to resolve all questions, and to discover by one’s own labor everything that the human mind can find in that science.
Letter to Hogelande, Feb. 8, 1640.
Our nature is such that we are deceived in things which are the most evident, and as consequence we would not have a true science but a simple persuasion even at the moment when we had derived [conclusions] from these [first] principles.
Letter to Regius, May 24, 1640. III, 64-65.
Thus [without the knowledge of God] I would never have a true and certain science of anything whatever, but only vague and inconstant opinions.
Meditations, V. IX, 55.
The certainty and the truth of every science depend only on the knowledge of the true God: so that before I knew this, I could not know any other thing perfectly.
Meditations, V. IX, 56.
I do not deny that an atheist could know clearly that the three angles of a triangle are equal to two right angles; but I maintain only that he does not know it by a true and certain science, because any piece of knowledge which can be rendered doubtful ought not to be called science.
Replies, II. IX, 111.
As for the sciences, which are nothing but the certain judgments that we base upon some preceding knowledge, some are derived from common things, which everyone has heard about, and others from rare and erudite experiments.
Search for Truth. X, 503.
See mathematics, universal; persuasion.
SCORN
See esteem.
SCRIPTURE
I believe that it is to apply Holy Scripture to an end for which God has not given it, and as a consequence to abuse it, to want to derive from it the knowledge of truths which belong only to human sciences, and which do not serve for our salvation.
Letter to °°°, Aug., 1638 (?). II, 348.
As soon as I see the word secret [arcanum] in some proposition, I begin to have a bad opinion of it.
Letter to Mersenne, Nov. 20, 1629. I, 78.
SECURITY
When hope is so strong that it entirely eliminates fear, it changes its nature and is called security or assurance. And when one is assured that what one wishes will come to pass, even though he continues to wish that it happen, he ceases nevertheless to be agitated by the passions of desire, which looks at the outcome with disquiet.
Passions, III, 166. XI, 457.
SEEDS OF KNOWLEDGE
See poets.
SEEDS OF THOUGHT
The human mind actually possesses something divine, in which the first seeds of thought have been implanted, so that they often produce their fruit spontaneously, however much they may have been neglected and stifled by study.
Rules, IV. X, 373.
SEEDS OF TRUTH
I am persuaded that certain primary seeds of truth are implanted by nature in the human mind, and that we suffocate them in us by reading and hearing so many errors of every sort; but these seeds grew so well in that rude and simple world of the ancients that the same mental light which showed them that they must prefer virtue to pleasure, and honesty to expediency, even though they did not know why this was so, also gave them true ideas in philosophy and mathematics, although they never were able to perfect these sciences.
Rules, IV. X, 376.
See first notions.
SELF-CAUSED
The words self-caused cannot in any way whatever be understood of the efficient cause, but solely [in such a way] that the inexhaustible power of God is the cause or the reason by which he has no need of cause.
Replies, IV. IX, 182.
See being by itself.
SENSATION
It is the soul which senses, and not the body: for it is easy to see that, when it is diverted by an ecstatic or deep contemplation, the whole body remains without sensation, even though various objects touch it.
Dioptrics, IV. VI, 109.
I do not recognize any other sensation than that which takes place in the brain.
Letter to Plempius, Oct. 3, 1637. I, 420.
There is found in me a certain passive faculty of sensation, i.e., of receiving and knowing the ideas of sensible things; but it would be useless to me, and I could not make use of it in any way, if there were not in me, or in another, an active faculty, capable of forming and producing these ideas.
Meditations, VI. IX, 63.
Actually, all the sensations of hunger, thirst, pain, etc., are nothing other than certain confused ways of thinking, which come from and depend upon the union and, as it were, the mixture, of the mind with the body.
Meditations, VI. IX, 64.
We perceive that the sensations of pain, and all others of similar nature, are not pure thoughts of the soul as distinct from the body, but confused perceptions of that soul which is really united to the body.
Letter to Regius, Jan., 1642(?). III, 493.
We can have a clear and distinct knowledge of the sensations, the emotions [affections] and the appetites, provided that we are careful not to include in the judgments that we base upon them more than what we know precisely by means of our understanding and of which we are assured by reason.
Principles, I, 66. IX2, 55.
In order that we may distinguish here what is clear in our sensations from what is obscure, we note, in the first place, that we clearly and distinctly know pain, color, and the other sensations, when we consider them simply as thoughts; but that, when we wish to judge that color, pain, etc., are things which subsist outside our thought, we do not conceive in any way what thing it is that is color, pain, etc.
Principles, I, 68. IX2, 56.
It is the various thoughts of our soul, which immediately follow the motions which are excited by the ends of the nerves in the brain, which we properly call our sensations, or rather the perceptions of our senses.
Principles, IV, 189. IX2, 310.
I distinguish seven principal sensations, two of which can be called internal [natural appetites and passions], and the five others external [touch, taste, odor, hearing and sight].
Principles, IV, 190. IX2, 311.
There is nothing in bodies which can excite any sensation in us, other than motion, shape or place, and the size of their particles.
Principles, IV, 198. IX2, 316.
The human soul separated from the body does not properly have sensation.
Letter to More, Aug., 1649. V, 402.
[The passions] can be called sensations, because they are received in the soul in the same way as are the objects of the external senses, and are not otherwise known by the soul.
Passions, I, 28. XI, 350.
SENSES
Although our external senses are applied to their objects through an action [or, more precisely, through a local motion], insofar as they are parts of the body, they never sense, properly speaking, other than passively, just as the wax receives the image from the seal.
Rules, XII. X, 412.
All the conduct of our life depends upon our senses, among which that of sight is the most universal and the most noble.
Discourse, VI. VI, 81.
The ideas that I received by the senses were much more lively, more precise, and even in their own way more distinct, than any of those which I could suppose by myself in meditation, or which I found imprinted in my memory.
Meditations, VI. IX, 60.
Everything that we perceive by means of our senses is related to the strict union of the soul with the body, and we ordinarily know by means of the senses what can be profitable or harmful to us in the external body, but not the nature of the body, except perhaps rarely and accidentally.
Principles, II, 3. IX 2, 64-65.
As for the external senses, everyone customarily counts five, because there are five different types of object which move the nerves, and because the impressions which come from these objects excite five different kinds of confused thoughts in the soul.
Principles, IV, 191. IX2, 312.
The soul does not sense insofar as it is in each part of the body, but solely insofar as it is in the brain, where the nerves, by their movements, communicate to it the various actions of the external objects which touch the parts of the body in which these nerves are inserted.
Principles, IV, 196. IX2, 314.
See consider.
SENSE, COMMON
The common sense [is] where the ideas are received.
Discourse, V. VI, 55.
It is certain that the seat of the common sense ought to be quite mobile, in order to receive all the impressions which come from the senses; but it ought to be such that it can be moved only by the [animal] spirits, which transmit these impressions, and the conarium [pineal gland] alone is of this sort.
Letter to Mersenne, Apr. 21. 1641. III, 362.
That faculty which is usually termed the common sense [is that] whereby impressions are received of imaginary things as much as of real things, so that they affect the mind—a faculty which philosophers commonly allow even to the brute creation.
Notes against a Program, VII. VIII 2, 356.
SENSE, GOOD
Good sense is the best-divided thing in the world: because everyone thinks that he is so well provided with it that even those who are most difficult to please in everything else do not usually want more of it than they have.
Discourse, I. VI, 1-2.
Just as there is nothing good in this world, except for good sense, which can be called absolutely good, there is also no evil, from which one cannot derive some advantage, if one has good sense.
Letter to Elisabeth, June, 1645. IV, 237.
See reason.
SERVILITY
As for servility, or vicious humility, it consists principally in that one thinks himself feeble and irresolute and that, as if he did not have the full use of his free will, he cannot prevent himself from doing things about which he knows that he will repent afterward; and also, in that he believes that he cannot subsist by himself, nor get along without many things, whose acquisition depends upon another.
Passions, III, 159. XI, 450.
SEX
With the difference in sex, which nature has given to men, as to the animals without reason, she has also given certain impressions in the brain, which, at a certain age and in certain times, make one consider himself as defective, and as if he were only the half of a whole, of which a person of the other sex ought to be the other half; in such a way that the acquisition of that half is confusedly represented by nature as the greatest of all the goods which can be imagined.
Passions, II, 90. XI, 395-396.
SHAME
Shame is composed of self-love and a pressing desire to avoid present infamy.
Passions, II, 117. XI, 415.
Shame is a species of sadness, founded upon the love of oneself, which comes from the opinion or fear that one will be blamed.
Passions, III, 205. XI, 482.
See pride.
SHAPE
Nothing is more easily sensed than shape: one actually touches it and sees it.
Rules, XII. X, 413.
The infinite number of shapes is sufficient to express all the differences among sensible things.
Rules, XII. X, 413.
We judge the shape of an object by our knowledge, or opinion, of the position of the various parts of the object, and not by their resemblance to pictures which are in the eye: for these pictures ordinarily only contain ovals and diamond-shapes, when they make us see circles and squares.
Dioptrics, VI. VI, 140.
The idea of shape is joined to the idea of extension and of substance, since it is impossible for me to conceive a shape, while denying that it has an extension, nor to conceive an extension, while denying that it is the extension of a substance.
Letter to Gibieuf, Jan. 19, 1642. III, 475.
It is not possible to conceive of shapes which do not have extension.
Rules, XII. X, 421.
SHREWDNESS
For me, the maxim that I have most often observed in all the conduct of my life, has been always to live virtuously and to believe that the principal shrewdness [finesse] is never to want to use shrewdness.
Letter to Elisabeth, Jan., 1646. IV, 357.
The sense [of sight] also depends in this machine [the body] upon two nerves, which must doubtless be composed of many tiny threads, the finest, and the easiest to move, that any can be; since they have as their end to report to the brain the various actions of the particles of the second element [air], which, following what I have said above, will give occasion to the soul, when it is united to the machine, to conceive the various ideas of colors and of light.
Treatise on Man. XII, 151.
The most subtle of all the senses is that of sight; for the optic nerves, which are its organs, are not moved by the air, nor by the other terrestrial bodies, but solely by the particles of the second element, which, passing through the pores of all the fluids and transparent membranes of the eyes, travel to these nerves, and, depending on the various ways in which they move it, make the soul sense all the variety of colors and of light.
Principles, IV, 195. IX2, 314.
SIGNS
Whatever does not require the immediate attention of the mind, which is nevertheless necessary for the conclusion of an argument, it is better to designate by very brief signs, rather than by complete figures.
Rules, XVI. X, 454.
Each thing that we must consider as a unit in order to resolve a difficulty can be designated by a unique sign, which can be made in any form we wish.
Rules, XVI. X, 455.
SIMPLE
Conscious as I am of my inadequacy, I have resolved that in my investigation into truth I shall follow obstinately such an order as will require me first to start with what is simplest and easiest, and never permit me to proceed farther until in the first sphere there seems to be nothing more to be done.
Rules, IV. X, 378-379.
We ought to give the whole of our attention to the simplest and most easily mastered things, and remain a long time in contemplation of them until we are accustomed to intuit the truth clearly and distinctly.
Rules, IX. X, 400.
Concerning things only insofar as they are conceived by the understanding, we call only those things “simple” which are known so clearly and distinctly that the mind cannot divide them into others which would be more distinctly known: of this nature are shape, extension, movement, etc.
Rules, XII. X, 418.
One cannot give any logical definition [of truth] which helps to know its nature. And I believe the same of many other things, which are quite simple and naturally known, such as shape, size, movement, place, time, etc., such that when one wishes to define these things, he obscures them and gets entangled.
Letter to Mersenne, Oct. 16, 1639. II, 597.
There are many things [e.g., doubt, thought, existence] which we make more obscure when we wish to define them, because, as they are very simple and very clear, it is impossible for us to know them and comprehend them better than by themselves.
Search for Truth. X, 523-524.
It is impossible to apprehend these [simple] things otherwise than by oneself, and to be persuaded otherwise than by his own experience, and by that conscience or interior witness which each man finds in himself when he examines any observation whatever; in such a way that, as it would be useless to define the color white to make a blind man understand, while for us to know it, it is enough to open our eyes and to see white, in the same way, to know what doubt and thought are, it is enough to doubt and to think.
Search for Truth. X, 524.
A composite entity is one in which are found two or more attributes, any one of which can be comprehended distinctly apart from the other, for it is from the fact that one can be thus known without the other that each of these constituent elements is seen to be, not a mode of the others, but a thing, or the attribute of a thing which can exist without that attribute. A simple entity is one in which such attributes are not found.
Notes against a Program, II. VIII 2, 350.
SIMPLE IDEAS
I do not completely understand the question that you ask me, namely whether our ideas are expressed by a simple term; for since words are the invention of men, one can always use one or many to explain the same thing; but I have explained in my Reply to the First Objections how a triangle inscribed in a square can be taken for a single idea or for many.
Letter to Mersenne, July 23, 1641. III, 417-418.
SIMPLE NATURES
Everything that we can know is composed of simple natures.
Rules, XII. X, 420.
The simple natures are completely known in themselves, and they never contain anything false.
Rules, XII. X, 420.
We can never understand anything other than the simple natures, and the sort of mixture or composition which can be made from them.
Rules, XII. X, 422.
No effort is required to know the simple natures, because they are sufficiently known in themselves.
Rules, XII. X, 425.
SIMPLE NOTIONS
We cannot seek the simple notions anywhere other than in our soul, which has them all in itself by its nature, but which does not always sufficiently distinguish one from another, or does not attribute them to the objects to which it should attribute them.
Letter to Elisabeth, May 21, 1643. III, 666-667.
When I said that the proposition, I think, therefore I am, is the first and most certain which presents itself to anyone who thinks in an orderly fashion, I did not for that reason deny that it was necessary to know in advance what thought, certainty, and existence were, and that in order to think one must exist, and other similar things; but, because these notions are so simple that, by themselves, they do not give us any knowledge of anything that exists, I did not judge that they had to be taken into consideration.
Principles, I, 10. IX2, 29.
See primitive notions.
SIMPLE THINGS
Of this type of thing [i.e., simple things] is corporeal nature in general, and its extension; together with the shape of extended things, their quantity or size, and their number; as also the place where they are, the time which measures their duration, and other similar things.
Meditations, I. IX, 15.
SIN
In everything where there is occasion to sin, there is indifference; and I do not believe that, to do wrong, there is need to see clearly that what we do is evil; it is enough to see it confusedly, or solely to recall that we have judged previously that it was, without seeing it in any way, that is, without paying attention to the reasons which prove it; for, if we saw it clearly, it would be impossible to sin, during the time that we saw it in that way; that is why it is said that every sinner is one through ignorance.
Letter to Mesland, May 2, 1644(?). IV, 117.
Sin actually results, in general, from ignorance, because no one can desire evil, insofar as it is evil.
Burman. V, 159.
SIZE
Size does not differ from that which has a given size, and number does not differ from what is numbered, except in our thought.
Principles, II, 8. IX2, 67.
SKY
Let us suppose that the matter of the sky is liquid, as well as that which composes the sun and the fixed stars.
Principles, III, 24. IX2, 112.
SLEEP
During sleep, the substance of the brain, which is resting, has the leisure to be nourished and repaired, since it is moistened by the blood which is contained in the tiny veins or arteries which appear in its exterior surface.
Treatise on Man. XI, 198.
I believe [the cause of sleep] to consist in the fact that, just as we see, sometimes, that the sails of ships fold up, because the wind does not have enough force to fill them, in the same way the animal spirits, which come from the heart, are no longer abundant enough to fill the marrow of the brain, and hold open all the pores; which then makes us sleep.
Letter to Newcastle, Apr., 1645(?). IV, 192.
SLEEPING
There are no conclusive indices, nor very certain marks, by which one can distinguish waking from sleeping.
Meditations, I. IX, 15.
SMOKE
Small particles of wood, mixed with air, compose the smoke, as the larger particles of the wood compose the ashes.
Letter to Mersenne, Oct. 20, 1642. III, 587.
I will not forget [the snow] whose particles have the shape of tiny six-pointed stars very perfectly proportioned, and which, even though they were not observed by the ancients, are nevertheless one of the rarest marvels of nature.
Meteorology, I. VI, 232.
SOCRATES
When we consider the ignorance, or rather the doubt of Socrates, we find that it became a question [for inquiry] as soon as Socrates, turning toward that doubt, began to ask whether it is true that he doubted all things, and replied affirmatively.
Rules, XIII. X, 432.
SOLES
Since the soles of our feet are accustomed to a rather heavy touch, because of the weight of the body that they sustain, we hardly sense that touch when we are walking; on the other hand, a very light and soft touch, when they are tickled, is almost unbearable to us, simply because it is not the ordinary thing for us.
Passions, II, 72. XI, 382.
SOLID
I do not find any difference between solid bodies and liquid bodies other than the fact that the particles of the one can be separated from the whole much more easily than those of the other.
The World, III. XI, 13
SOLIDITY
On this earth, pieces of gold, of lead, or of some other metal, conserve their agitation [i.e., state of motion] well, and have much more force with which to continue their motion, when they are once moved, than have pieces of wood or stones of the same size and shape, which makes us judge that they are more solid: that is, that these metals have more of the matter of the third element in them, and fewer pores which are filled with the matter of the first or second element.
Principles, III, 122. IX2, 175.
SOPHISMS
The subtlest sophisms ordinarily deceive almost no one who makes use of pure and simple reason, but deceive only the sophists themselves.
Rules, X. X, 406.
SOUL
When the rational soul is in this machine [the body], it will have its principal seat in the brain.
Treatise on Man. XI, 131.
The soul is a substance distinct from the body, whose nature is nothing other than thinking.
Letter to Mersenne, Feb. 27, 1637. I, 349.
The soul is a being or substance which is not at all bodily, and its nature is only thinking; it is the first thing that one can know with certainty.
Letter to °°°, May, 1637. I, 353.
This ego, that is, the soul by which I am what I am, is entirely distinct from the body, and it is even easier to know than the body, and even if the body did not exist, the soul would not cease to be what it is.
Discourse, IV. VI, 33.
The rational soul cannot in any way be derived from the potentiality of matter, as can the other things about which I have spoken, but it must have been expressly created; and it is not enough that it be located in the human body like a pilot in his ship, except perhaps to move its limbs, but it must also be joined and united more closely with the body in order to have, beyond that, sensations and appetites similar to ours, and thus to compose a true man.
Discourse, V. VI, 59.
Our [soul] is of a nature which is entirely independent of the body and, as a consequence, it is not subject to dying with it.
Discourse, V. VI, 59.
The soul, residing in the brain, can thus, by the intermediary of the nerves, receive impressions from external objects.
Dioptrics, IV. VI, 109.
From the fact alone that one conceives clearly and distinctly the two natures of the soul and the body as diverse, one knows that truly they are diverse, and, as a consequence, that the soul can think without the body, even though, when it is joined to the body, it can be disturbed in its operations by the malfunctioning of the body’s organs.
Letter to Reneri, Apr.-May, 1638. II, 38.
I prefer to think that the wax, simply because of its flexibility, receives all sorts of shapes, and that the soul acquires all its knowledge by the reflection that it makes, either upon itself concerning intellectual things, or upon the various dispositions of the brain to which it is joined, concerning corporeal things, whether these dispositions depend upon the senses or upon other causes.
Letter to Mersenne, Oct. 16, 1639. II, 598.
Anima [soul] in good Latin signifies air, or the wind from the mouth; from which I believe that it has been transferred to signify the mind, and it is for that reason that I said that it is often taken to be a corporeal thing.
Letter to Mersenne, Apr. 21, 1641. III, 362.
I do not admit that the vegetative and sensitive force in the brutes merits the name of soul, as the soul merits that name in man; but the common people have wished it thus, because they have not known that the beasts have no soul and as a consequence the name soul is equivocal with regard to man and beast.
Letter to Regius, May, 1641. III, 370.
There is only one soul in man, i.e., the rational soul; because the only human actions that should be counted are those which depend on reason. With regard to the vegetative and motive force of the body to which they [the Aristotelians] give the name of vegetative and sensitive soul in the plants and in the brutes, they are also in man; but they should not be called souls in man, because they are not the first principle of his actions, and they are of quite a different type from the rational soul.
Letter to Regius, May, 1641. III, 371.
I have demonstrated that the soul is nothing other than a thing which thinks; it is therefore impossible that we can ever think of anything without having at the same time the idea of our soul, as of a thing capable of thinking of all that we think about.
Letter to Mersenne, July, 1641. III, 394.
The human body can easily perish, but the mind, or the soul of man (I do not distinguish between them), is immortal by its very nature.
Meditations, Summary. IX, 10.
It is certain that this ego, that is, my soul, by which I am what I am, is entirely and truly distinct from my body, and that it could be or exist without it.
Meditations, VI. IX, 62.
The reason for my belief that the soul always thinks is the same that makes me believe that light always lights, even though there are no eyes that see it; that warmth is always warm, even though no one is warmed by it; that body, or extended substance, always has extension; and generally, that whatever constitutes the nature of a thing is always in it, as long as it exists; so that it would be easier for me to believe that the soul stopped existing, when one says that it stops thinking, than to believe that it exists without thinking.
Letter to Gibieuf, Jan. 19, 1642. III, 478.
The numerical unity of the body of a man does not depend upon its matter, but upon its form, which is the soul.
Letter to Mesland, 1645 or 1646. IV, 346.
If [beasts] thought as we do, they would have an immortal soul as we do; but this is not plausible, because there is no reason for believing this of some animals without believing it of all, and because there are many animals which are too imperfect for us to believe it of them, like the oysters, the sponges, etc.
Letter to Newcastle, Nov. 23, 1646. IV, 576.
[The properties of the soul] are all to be subordinated to two predominant properties, one of which is the perception of the understanding, the other the determination of the will.
Notes against a Program, XVI. VIII 2, 363.
The soul, being a thinking thing, is also, besides thought, a substance which thinks.
Burman. V, 156.
SOUL AND BODY
At the first moment that our soul was joined to the body, it is likely that it sensed joy, and immediately, afterward, love; then perhaps also hate, and sadness.
Letter to Chanut, Feb. 1, 1647. IV, 604.
There is a connection between our soul and our body such that when we have once joined some corporeal action with some thought, one of the two is never afterward presented to us, without the other being presented also.
Passions, II, 107. XI, 407.
See sensations, passions.
SOUL, RATIONAL AND SENSITIVE
It is only the clash between the movements that the body tends to excite, by means of its [animal] spirits, and those the soul makes by means of its will, at the same time in the [pineal] gland, which is customarily imagined to constitute all the combats between the inferior part of the soul, which is called sensitive, and the superior part, which is rational, or between the natural appetites and the will. For there is only one soul in us, and that soul does not have various parts: the same soul that is sensitive is rational, and all its appetites are acts of will.
Passions, I, 47. XI, 364.
SOUND
The most notable properties of sound are two, namely, its differences with respet to time or duration, and with respect to the force or intensity of sound, considered insofar as it is low or high.
Compendium Musicae. X, 89.
One sound is to another as one string [on a musical intrument] is to another; for each string contains in itself all the other lengths of string which are less than itself, and none of those which are greater. As a consequence, then, all the higher sounds are contained in the lower, but the reverse is not true: all the lower sounds are not contained in the higher.
Compendium Musicae. X, 97.
And note that a single [vibration] cannot make any one hear anything other than a dull sound, which passes away in a moment, and in which there is no variation, other than being louder or softer, according to whether the ear is struck harder or more softly; but that, when many such blows follow one another, one can see with the naked eye that the strings of an instrument vibrate, and that bells shake when they resound; and these tiny shakings compose a sound, which the soul judges sweeter or cruder, according to whether they are more or less equal among themselves.
Treatise on Man. XI, 149-150.
I judge that the experiment is correct, which shows that sounds do not travel more quickly with the wind than against the wind; for the movement of sound is something quite different from that of the wind.
Letter to Mersenne, Mar., 1636. I, 341.
SPACE
As for the question of whether there would be a real space, as there is now, in case God had created nothing, even though such a question exceeds the limits of the human mind, and is not something that can be reasonably debated, like questions concerning the infinite, nevertheless I believe that it does not exceed the bounds of our imagination, like questions of the existence of God and of the human soul, and that our understanding can attain the truth about them, which is, at least in my opinion, that not only would there be no space, but even the truths which are called eternal, like the whole is greater than its parts, etc., would not be truths, if God had not established them in that way.
Letter to Mersenne, May 17, 1638. II, 138.
Space or interior place does not differ from the body which is comprised in that space, except by our thought.
Principles, II, 10. IX2, 68.
We never distinguish space from extension in length, breadth and depth; but we sometimes consider the place as if it were in the thing which is placed, and sometimes also as if it were external to it. The interior does not differ from the space, but we sometimes take the exterior, either to be the surface which inmmediately surrounds the thing which is placed (and it is to be noted that, for the surface, one ought not to understand any part of the body which surrounds it, but only the extremity which is between the body which surrounds and that which is surrounded, which is nothing but a mode or an aspect), or to be the surface in general, which is not part of one body rather than another, and which seems always the same, as long as it is the same size and shape.
Principles, II, 15. IX2, 71.
SPACES, IMAGINARY
Supposing the world finite, one imagines beyond these limits some spaces which have their three dimensions, and thus which are not purely imaginary, as the philosophers call them.
Letter to Chanut, June 6, 1647. V, 52.
SPEECH
Speech is the unique sign and the sole assured mark of the thought which is hidden in the body; but all men, the most stupid and insane, even those who are deprived of the organs of language and speech, make use of signs, while the beasts do nothing similar, so that speech may be taken as the true difference between man and beast.
Letter to More, Feb. 5, 1649. V, 278.
SPIRITS
The more lively and subtle particles, that is, those which are quite fine, and together very solid and agitated, I will always henceforth call spirits.
Description of Human Body, IV. XI, 260.
What I here call [animal] spirits are only bodies, and they have no other property than that of being very small, and moving very quickly, like the particles of flame which come from a torch.
Passions, I, 10. XI, 335.
SPIRITS, ANIMAL
As for the particles of blood which penetrate to the brain, they do not serve only to nourish and maintain its substance, but principally also to produce there a certain very subtle wind, or rather a very lively and very pure flame, which is called the animal spirits.
Treatise on Man. XI, 129.
It is not the mind [or the soul] which immediately moves the external members [of our bodies], but it only determines the course of that very subtle liquid which is called the animal spirits, which, flowing continually from the heart through the brain into the muscles, is the cause of all the movements of our members.
Replies, IV. IX, 178.
What [the doctors] call the animal spirits are nothing other than the most lively and subtle parts of the blood, which are separated from the grosser parts, as they are sifted out in the tiny branches of the carotid arteries, and which pass from there into the brain, from which they are distributed by the nerves into all the muscles.
Letter to Newcastle, Apr., 1645 (?). IV, 191.
The most agitated and lively particles of the blood, when they are carried to the brain by the arteries that come from the heart most directly of all, compose an air or a very subtle wind, which is called the animal spirits; which, dilating the brain, render it proper to receive the impressions of external objects, and also those of the soul, that is to say, to be the organ or the seat of the common sense, imagination, and memory.
Description of Human Body, I. XI, 227.
SPIRITS, VITAL
What the doctors call the vital spirits are nothing other than the blood contained in the arteries, which does not differ from that of the veins, except in that it is rarer and warmer, because it has just been warmed and dilated in the heart.
Letter to Newcastle, Apr., 1645 (?). IV, 191.
Water is always similar to water, but it has quite another taste when one drinks it at the spring, than when he drinks it from a jug or from a stream.
To Beeckman, Oct. 17, 1630. I, 160.
STARS
It is quite likely that the surfaces of the skies, which are composed of a very fluid material, and which never stop moving, must always tremble and form waves somewhat; and, as a consequence, the stars that one sees through them must appear twinkling and as though trembling.
The World, XV. XI, 108.
STIFF
The property of bending and springing back, which can be briefly called being stiff, is generally found in all bodies of which the particles are joined by the perfect contact of their little surfaces, simply by the interlacing of their branches.
Principles, IV, 132. IX2, 270.
See flint.
SUBSTANCE
Everything in which there resides immediately, as in its subject, or by which there exists, something that we conceive, i.e., some property, quality, or attribute, of which we have in us a real idea, is called Substance. For we do not have any other idea of substance in a precise sense, except that it is a thing in which there exists formally, or eminently, that which we conceive, or what is objectively in one of our ideas, inasmuch as the natural light teaches us that nothing can have no real attribute.
Replies, II. IX, 125.
From the fact that we perceive some forms, or attributes, which must be attached to something if they are to exist, we call by the name Substance that thing to which they are attached.
Replies, IV. IX, 172-173.
We know a thing or substance better when we notice more properties in it.
Principles, I, 11. IX2, 29.
When we conceive substance, we conceive only a thing which exists in such a way that it has no need of anything but itself for existence. In this, there could be some obscurity concerning the explanation of the phrase, “has no need of anything but itself”; for, properly speaking, only God is thus, and there is no created thing which could exist a single moment without being sustained and conserved by his power. This is why the School is correct in saying that the word substance is not “univocal” with regard to God and creatures, that is, that there is no signification in this word which we conceive distinctly, which applies to him and to them; but because among the created things some are of such a nature that they cannot exist without some others, we distinguish them from those which have no need other than the ordinary concurrence of God, and we call these substances, and the others the qualities or attributes of these substances.
Principles, I, 51. IX2, 47.
Those [ideas] which represent substances to me are doubtless something more, and contain in themselves (so to speak) more objective reality, i.e., participate by representation in more degrees of being or perfection, than those which represent only modes or accidents.
Meditations, III. IX, 31-32,
SUN
The rays of the Sun have a most remarkable advantage in comparison with those of a torch: which is that their force does not diminish, and even increases more and more, as they are farther and farther from the Sun.
The World, XV. XI, 109.
We may believe that the sun is composed of matter which is quite liquid, the particles of which are extremely agitated, so that they carry with them the particles of the sky in the vicinity of the sun and which surround them; but, in common with the fixed stars, the sun does not pass from one part of the sky to another.
Principles, III, 21. IX2, 111.
The sun has no need of fuel, as does flame.
Principles, III, 22. IX2, 111.
SUNSPOTS
You do not tell me which side the poles are on, of the band along which the sunspots have been seen, but I do not doubt that they correspond in some way to those of the earth, and their ecliptic to our own.
Letter to Mersenne, Mar. 4, 1630. I, 125.
Let us think also that the opaque bodies which are seen with telescopes upon the sun, and which are named its spots, move over its surface, and take twenty-six days to complete their revolution.
Principles, III, 32. IX2, 116.
SUPERSTITION
It is good to have examined all sciences, even the most superstitious and false, in order to know their value and to guard oneself against being deceived.
Discourse, I. VI, 6.
SUPPOSITIONS
If some of the things about which I have spoken, at the beginning of the Dioptrics and the Meteorology are surprising at first, because I call them suppositions, and do not seem to have any desire to prove them, one should have enough patience to read the whole with attention, and I hope that he will find himself satisfied with it.
Discourse, VI. VI, 76.
I imitate the astronomers, who, even though their suppositions are almost all false or uncertain, nevertheless, because they are connected with various observations that they have made, can derive many consequences from them which are quite true and quite assured.
Discourse, VI. VI, 83.
It is to be noted that although I speak of suppositions, I nevertheless do not make any [here] whose falsehood, even though it is well known, can give occasion for doubting the truth of the conclusions which are derived from them.
Principles, III, 47. IX2, 126.
SURFACE
There is no other thing by which our senses are touched, except the surface which is the limit of the dimensions of the body which is sensed or perceived by the senses.
Replies, IV. IX, 192.
The word surface is taken in two ways by the mathematicians: namely, either for the body of which only the length and breadth are being considered, without regard to its depth, even though it is not denied that there is one; or it is taken solely as a mode of body, and then all depth is denied to it.
Replies, VI. IX, 234.
By the word surface, I do not understand some substance of real nature which could be destroyed by the omnipotence of God, but solely a mode or a fashion of being, which cannot be changed without changing that in which or by which it exists; as it implies a contradiction to say that the square shape of a piece of wax is taken from it and that nevertheless none of the parts of the wax change their places.
Letter to Mesland, Feb. 9, 1644. IV, 163-164.
SURPRISE
[Wonder has] a great deal of force, because of surprise, that is, the sudden and unexpected arrival of the impression which changes the motion of the [animal] spirits; this surprise is proper and particular to that passion.
Passions, II, 72. XI, 381.
SYLLOGISMS
The dialecticians cannot construct anything according to the rules of the syllogism, which will have a true conclusion, if they do not already have the material for it, that is, if they do not know in advance that same truth which they are deriving.
Rules, X. X, 406.
SYLLOGISMS, PROBABLE
We do not condemn that method of philosophizing which others have already discovered and those weapons of the schoolmen, probable syllogisms, which are so well suited for polemics. They indeed give practice to the wits of youths and, producing emulation among them, act as a stimulus; and it is much better for their minds to be moulded by opinions of this sort, uncertain though they appear, as being objects of controversy among the learned, than to be left entirely to their own devices.
Rules, II. X, 363-364.
SYNTHESIS
Synthesis follows a path quite different [from that of analysis], as though it were examining causes by their effects (even though the proof that it contains is often also of effects by their causes), and truly demonstrates what is contained in its conclusions, and serves as a long sequence of definitions, presuppositions, axioms, theorems, and problems, so that, if some consequences are denied, it shows how they are contained in their antecedents, and how it forces the consent of the reader, however obstinate and opinionated he might be; but it does not give, as does analysis, a complete satisfaction to the minds of those who desire to learn, because it does not teach the method by which the subject has been invented.
Replies, II. IX, 122.
See analysis.