I always like to think on a problem before reading about it.

To reason logically is so to link one's propositions that each should contain the reason for the one succeeding it, and should itself be demonstrated by the one preceding it. Or at any rate, whatever the order adopted in the construction of one's own exposition, it is to demonstrate judgments by each other.

I engage my subjects in conversation, patterned after psychiatric questioning, with the aim of discovering something about the reasoning underlying their right but especially their wrong answers.

Jean Piaget Quotes