‘The gods plant reason in mankind, of all good gifts the highest.’ So said the tragic poet Sophocles in the 5th century BC, echoing an age-old view of the centrality of reason and rationality to mankind’s understanding of itself and its position in the world. Sophocles’ fellow Greeks generally concurred. Pythagoras, a shadowy figure from the 6th century BC, fell under the spell of numbers and their relations and is one of earliest thinkers known to venerate the powers of reason. Plato, in the 4th century BC, thought that the exercise of reason was the highest human good, as did his pupil Aristotle, who argued that reason was the very essence of a person – the aspect that set humans apart from other animals – and that its proper function was the key to man’s well-being and happiness.
Reason lost none of its allure in the modern period, and from the 17th century it became enshrined as the supreme human attribute in the Enlightenment, which was accordingly known also as the Age of Reason. But there has been less agreement about the precise role of reason in the proper functioning of humans. In particular, reason has often been opposed to sensory perception and experience, broadly interpreted, as the most appropriate means of acquiring knowledge of how things stand in the world and how best humans should conduct themselves in it.
Rationalism and empiricism The Age of Reason was so called because its pioneers, first in England and a little later in Scotland and in continental Europe, saw themselves as raising the torch of reason to dispel the shadows of prejudice and superstition that had enveloped (as they supposed) the previous medieval period. Henceforth, beliefs would be tested and approved on the touchstone of reason, rather than on the basis of clerical authority or tradition. The progress of science suggested, in general, that the world was intelligibly structured and that its secrets would be revealed by the power of rational thought. One of the greatest figures of the Enlightenment, the German philosopher Immanuel Kant, saw the new age as mankind’s emergence from its infancy – a period of immaturity in which people lacked the ‘resolve and courage to use [their reason] without the guidance of another’.
From early in the Enlightenment, however, there were signs of a rift between rationality and rationalism. Rationality – which required that beliefs be based on a proper evaluation of available evidence, that alternative explanations be considered, and so on – was widely accepted as the defining virtue of the age. In contrast, rationalism – the more specific view that reason is in some way a uniquely privileged means of apprehending certain fundamental truths – was immediately contentious. Descartes had founded his philosophical project on the rock of rational certainty, which was reached by reason alone and from which he hoped to corroborate all knowledge, including knowledge derived from the senses. The primacy he gave to reason in the acquisition of knowledge was broadly accepted by the other so-called Continental rationalists, Leibniz and Spinoza, but central aspects of his thesis were opposed by the British empiricists, Locke, Berkeley and Hume. Of the latter, Hume was most prominent in the task of limiting the scope of rationality, denying that it had an essential role in the normal, empirical (experience-based) processes by which beliefs are formed. He also insisted that reason’s part in deciding moral questions was secondary to that of ‘sympathy’ or human sentiment.
‘Rationalism is a hideous monster when it claims for itself omnipotence. Attribution of omnipotence to reason is as bad a piece of idolatry as is worship of stock and stone believing it to be God. I plead not for the suppression of reason, but for a due recognition of that in us which sanctifies reason.’
Mahatma Gandhi, 1926
The most influential attempt to expound a rationalist theory of knowledge was made by Kant in his Critique of Pure Reason (1781). In a consciously grandiose move which he likened to Copernicus’ revolution in astronomy, Kant set out to show that all previous philosophy had been done back to front: the underlying assumption had been that ‘all our knowledge must conform to objects’ – and for that reason it had failed – so he now suggested that the assumption be reversed and objects made to conform to our knowledge. There are, he argues, certain concepts or categories of thought, such as substance and causation, which we cannot learn from the world but which we are required to use in order to make sense of it. We can be certain that our logic and mathematics (for instance) will not become invalidated in the light of experience precisely because the patterns and conformities on which they are based have been abstracted from our own minds and imposed on the ‘great blooming, buzzing confusion’ of perceptions. And it is precisely this capacity to impose order and structure on this chaos of sensation that constitutes our powers of reasoning, or rationality.
the condensed idea
Master or slave of the passions?