Reason acts slowly and with so many views, on so many principles, which it ought always to keep before it, that it constantly slumbers and goes astray, from not having its principles at hand. The heart does not act thus, it acts in a moment, and is always ready to act. We must then place our faith in the heart, or it will be always vacillating.
Men often mistake their imagination for their heart, and they believe they are converted as soon as they think of being converted.
Those who are accustomed to judge by the heart do not understand the process of reasoning, for they wish to understand at a glance, and are not accustomed to seek for principles. And others on the contrary, who are accustomed to reason by principles, do not at all understand the things of the heart, seeking principles and not being able to see at a glance.
If we wished to prove those examples by which we prove other things, we should have to take those other things to be examples. For as we always believe the difficulty is in the matter we wish to prove, we find the examples clearer and aids to demonstration.
Thus when we wish to demonstrate a general proposition, we must give the rule special to a case, but if we wish to demonstrate a particular case, we must begin with the particular rule. For we always find the thing obscure which we wish to prove, and that clear which we employ as proof; for when a matter is proposed for proof we first fill ourselves with the imagination that it is therefore obscure, and on the contrary that what is to prove it is clear, and so we understand with ease.
Far from believing a thing because you have heard it, you ought to believe nothing without having put yourself in the same position as if you had never heard it.
What should make you believe is your own assent to yourself, and the constant voice of your reason, not that of others.
Belief is so important!
A hundred contradictions might be true.