Those who reason most powerfully and are the most successful at ordering their thoughts so as to make them clear and intelligible will always be best… - René Descartes

But as soon as I had finished my course of study, at which time it is usual to be admitted to the ranks of the well educated, I completely changed my opinion, for I found myself bogged down in so many doubts and errors, that it seemed to me that having set out to become learned, I had derived no benefit from my studies, other than that of progressively revealing to myself how ignorant I was.

Η ικανότητα να κρίνει κανείς ορθά και να διακρίνει το σωστό από το λάθος- γεγονός στο οποίο ακριβώς εγκείται αυτό που ονομάζεται κοινός νους και λογική- είναι από τη φύση της ίδια σε όλυος τους ανθρώπους, και ότι, για τον λόγο αυτόν, η διαφορετικότητα των απόψεων μας δεν εξαρτάται από το γεγονός ότι κάποιοι είναι περισσότερο λογικοί απ' ό,τι άλλου, παρά μόνο από το ότι ακολουθούμε με ετις σκέψεις μας διαφορετικούς δρόμους και δεν λαμβάνουμε υπόψη μας τα ίδια πράγματα.

The majority of men is composed of two classes, for neither of which would this be at all a befitting resolution: in the first place, of those who with more than a due confidence in their own powers, are precipitate in their judgments and want the patience requisite for orderly and circumspect thinking; whence it happens, that if men of this class once take the liberty to doubt of their accustomed opinions, and quit the beaten highway, they will never be able to thread the byway that would lead them by a shorter course, and will lose themselves and continue to wander for life; in the second place, of those who, possessed of sufficient sense or modesty to determine that there are others who excel them in the power of discriminating between truth and error, and by whom they may be instructed, ought rather to content themselves with the opinions of such than trust for more correct to their own reason.