When the thing taken into union is perfectly adapted to that which receives it, the result is delight and pleasure and satisfaction.

A bird is an instrument working according to mathematical law, which instrument it is within the capacity of man to reproduce with all its movements, but not with a corresponding degree of strength, though it is deficient only in the power of maintaining equilibrium. We may therefore say that such an instrument constructed by man is lacking in nothing except the life of the bird, and this life must needs be supplied from that of man.

The organ of perception acts more readily than judgment.

Just as iron rusts from disuse... even so does inaction spoil the intellect.

Reprove your friend in secret and praise him openly.

I abhor the supreme folly of those who blame the disciples of nature in defiance of those masters who were themselves her pupils

Those who become enamoured of the art, without having previously applied to the diligent study of the scientific part of it, may be compared to mariners who put to the sea in a ship without rudder or compass and therefore cannot be certain of arriving at the wished for port.