One can have no more mastery over the environment, than one has over himself.

The motions of men must be such as suggest their dignity or their baseness.

Every now and then go away, have a little relaxation, for when you come back to your work your judgment will be surer. Go some distance away because then the work appears smaller and more of it can be taken in at a glance and a lack of harmony and proportion is more readily seen.

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.

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.

A good memory, which nature has endowed us with, causes things long past to seem present.

Learning never exhausts the mind.