Every human perfection is linked to an error which it threatens to become. - Arthur Schopenhauer

Whoever heard me assert that the grey cat playing just now in the yard is the same one that did jumps and tricks there five hundred years ago will think whatever he likes of me, but it is a stranger form of madness to imagine that the present-day cat is fundamentally an entirely different one.

Truth that has been merely learned is like an artificial limb, a false tooth, a waxen nose; at best, like a nose made out of another's flesh; it adheres to us only because it is put on. But truth acquired by thinking of our own is like a natural limb; it alone really belongs to us. This is the fundamental difference between the thinker and the mere man of learning. The intellectual attainments of a man who thinks for himself resemble a fine painting, where the light and shade are correct, the tone sustained, the colour perfectly harmonised; it is true to life. On the other hand, the intellectual attainments of the mere man of learning are like a large palette, full of all sorts of colours, which at most are systematically arranged, but devoid of harmony, connection and meaning.

To be alone is the fate of all great minds — a fate deplored at times, but still always chosen as the less grievous of two evils.