Deep0 's Key Ideas from Discours de la méthode/Discourse on the Method (French/English Bilingual Text)
by René Descartes

Descartes in his book writes about four rules, for better understanding, if what being said is true, or can be true:

1. Never accept nothing, until you will find out if this can be true. So it means, never make fast decisions, regarding what's being said.
2. Every hard analysed thing should be split up in many parts, for better understanding.
3. Follow some kind of thinking order, starting with the easiest and step by step going for harder things.
4. Always do calculating about detailed reviews, to be sure, that nothing is missed.