Every instrument requires to be made by experience.
1157.
The man who blames the supreme certainty of mathematics feeds on confusion, and can never silence the contradictions of sophistical sciences which lead to an eternal quackery.
1158.
There is no certainty in sciences where one of the mathematical sciences cannot be applied, or which are not in relation with these mathematics.
1159.
Any one who in discussion relies upon authority uses, not his understanding, but rather his memory. Good culture is born of a good disposition; and since the cause is more to be praised than the effect, I will rather praise a good disposition without culture, than good culture without the disposition.
1160.
Science is the captain, and practice the soldiers.
1161.