Our observation of nature must be diligent, our reflection profound, and our experiments exact. We rarely see these three means combined; and for this reason, creative geniuses are not common.

Denis Diderot
Profession: Philosopher
Nationality: French
Some suggestions for you :
Poetry must have something in it that is barbaric, vast and wild.
The God of the Christians is a father who makes much of his apples, and very little of his children.
Evil always turns up in this world through some genius or other.
It is not human nature we should accuse but the despicable conventions that pervert it.
His hands would plait the priest's guts, if he had no rope, to strangle kings.
Gaiety is a quality of ordinary men. Genius always presupposes some disorder in the machine.
Sentences are like sharp nails, which force truth upon our memories.