Having wandered some distance among gloomy rocks, I came to the entrance of a great cavern ... Two contrary emotions arose in me: fear and desire--fear of the threatening dark cavern, desire to see whether there were any marvelous things in it.

Nature varies the seed according to the variety of the things she desires to produce in the world.

The eye, the window of the soul, is the chief means whereby the understanding can most fully and abundantly appreciate the infinite works of Nature; and the ear is second.

Inaction saps the vigor of the mind.

Be a mirror, absorb everything around you and still remain the same

Necessity is the mistress and guide of nature.

The Bactrian have two humps; the Arabian one only. They are swift in battle and most useful to carry burdens. This animal is extremely observant of rule and measure, for it will not move if it has a greater weight than it is used to, and if it is taken too far it does the same, and suddenly stops and so the merchants are obliged to lodge there.