Descartes is rightly regarded as the father of modern philosophy primarily and generally because he helped the faculty of reason to stand on its own feet by teaching men to use their brains
in place whereof the Bible, on the one hand, and Aristotle, on the other, had previously served.
To gain anything we have longed for is only to discover how vain and empty it is; and even though we are always living in expectation of better things, at the same time we often repent and long to have the past back again.
For an act to be moral the intention must be based on compassion, not duty. We do something because we want to do it, because we feel we have to do it, not because we ought to do it. And even if our efforts fail - or we never even get to implement them - we are still moral because our motivation was based on compassion.
Great minds are related to the brief span of time during which they live as great buildings are to a little square in which they stand: you cannot see them in all their magnitude because you are standing too close to them.
Memory works like the collection glass in the Camera obscura: it gathers everything together and therewith produces a far more beautiful picture than was present originally.
To truth only a brief celebration of victory is allowed between the two long periods during which it is condemned as paradoxical, or disparaged as trivial.
Every man takes the limits of his own field of vision for the limits of the world. This is an error of the intellect as inevitable as that error of the eye which lets you fancy that on the horizon heaven and earth meet.
If children were brought into the world by an act of pure reason alone, would the human race continue to exist? Would not a man rather have so much sympathy with the coming generation as to spare it the burden of existence, or at any rate not take it upon himself to impose that burden upon it in cold blood?
It is, indeed, only in old age that intellectual men attain their sublime expression, whilst portraits of them in their youth show only the first traces of it.