Leonardo: Philosophy

NATURE IS FULL OF INFINITE CAUSES WHICH WERE NEVER SET FORTH IN EXPERIENCE

When you wish to produce a result by means of an instrument do not allow yourself to complicate it by introducing many subsidiary parts but follow the briefest way possible, and do not act as those do who when they do not know how to express a thing in its own proper vocabulary proceed by a method of circumlocution and with great prolixity and confusion.
                                c.a. 206 v.a

Aristotle in the Third [book] of the Ethics: man is worthy of praise and blame solely in respect of such actions as it is within his power to do or to abstain from.
                                c.a. 289 v.c

Our judgment does not reckon in their exact and proper order things which have come to pass at different periods of time; for many things which happened many years ago will seem nearly related to the present, and many things that are recent will seem ancient, extending back to the far-off period of our youth.  And so it is with the eye, with regard to distant things, which when illumined by the sun seem near to the eye, while many things which are near seem far off.
                                c.a. 29 v.a