Il est bon de savoir quelque chose des moeurs de divers peuples, afin de juger des nôtres plus sainement, et que nous ne pensions pas que tout ce qui… - René Descartes

The very desire to seek the truth often causes people, who do not know how it should be sought correctly, to make judgements about things that they do not perceive and in that way they make mistakes.

But what then am I? A thing that thinks. What is that? A thing that doubts, understand, affirms, denies, wills, refuses, and that also imagines and senses.

Therefore from the fact alone that I know that I exist and that, at the same time, I notice absolutely nothing else that belongs to my nature apart from the single fact that I am a thinking thing, I correctly conclude that my essence consists in this alone, that I am a thinking thing.