Of the four elements water is the second in weight and the second in respect of mobility. It is never at rest until it unites with the sea.

...The world wouldn't be the world, without trouble.

Study without desire spoils the memory, and it retains nothing that it takes in.

I am never weary of being useful... In serving others I cannot do enough. No labor is sufficient to tire me.

It is no small benefit on finding oneself in bed in the dark to go over again in the imagination the main lines of the forms previously studied, or other noteworthy things conceived by ingenious speculation.

Feathers shall raise men even as they do birds towards heaven :- That is by letters written with their quills.

To me it seems that those sciences are vain and full of error which are not born of experience, mother of all certainty, first-hand experience which in its origins, or means, or end has passed through one of the five senses.