Weight is caused by one element being situated in another; and it moves by the shortest line towards its centre, not by its own choice, not because the centre draws it to itself, but because the other intervening element cannot withstand it.

Truth was always but the daughter of time.

The light and heat of the universe comes from the sun, and its cold and darkness from the withdrawal of the sun.

The color of the object illuminated partakes of the color of that which illuminates it.

You grow in reputation like bread in the hands of a child.

O speculators about perpetual motion, how many vain chimeras have you created in the like quest? Go and take your place with the seekers after gold.

Test knowledge through experience, be prepared to make mistakes, and be persistent about it.