Why Descartes Matters

His metaphysics, as ingenious and new as his physics, had approximately the same fate; and it is with approximately the same reasons that we can justify it. For such is today the fortune of this great man that after having had countless followers he is practically reduced to a few apologists. He was without doubt mistaken in assuming the existence of innate ideas: but if he had retained from the peripatetic sect [the Aristotelians] the only truth that they taught about the origin of ideas in the senses, perhaps the errors, which would dishonor this truth because of its association with it, would have been much more difficult to eradicate. Descartes dared at least to teach good minds how to shake off the yoke of scholasticism, public opinion, and authority; in a word, certain prejudices and barbaric attitudes. From this revolt, whose fruits we are now reaping, philosophy received from him a service much more difficult perhaps to render than all those which it owes to his illustrious successors. We can consider him as the head of a group of conspirators, the first to have the courage to rise against a despotic and arbitrary power, and while preparing a brilliant revolution, to have laid the foundations of a more just and valid government which he was unable to see established. If he finally believed that he had explained everything, at least he began by doubting everything; and the arms that we use to combat him do not belong to him any the less because we turn them against him. Moreover, when absurd opinions have become inveterate, we are sometimes forced to replace them with other errors (if we can do no better) in order to disabuse the human race. The uncertainty and vanity of the mind are such that it must always entertain an opinion: it is a child that must be presented with a toy so that we can take away a dangerous weapon; he will lay aside the toy himself when the age of reason is attained. In putting philosophers, or those who believe they are, on a false scent, we teach them at least to mistrust their own understanding, and this disposition is the first step toward the truth. Consequently Descartes was persecuted in his lifetime as if he had come to bring the truth to mankind.

Descartes is mocked for looking for innate ideas in the mind, but this is a minor infraction for the revelation he provided that we cannot trust our senses in any way.