Equality consists in the same treatment of similar persons.

The virtue of a faculty is related to the special function which that faculty performs. Now there are three elements in the soul which control action and the attainment of truth: namely, Sensation, Intellect, and Desire. Of these, Sensation never originates action, as is shown by the fact that animals have sensation but are not capable of action.

...The entire preoccupation of the physicist is with things that contain within themselves a principle of movement and rest.

In educating the young we steer them by the rudders of pleasure and pain

Philosophy begins with wonder.

The happy life is thought to be one of excellence; now an excellent life requires exertion, and does not consist in amusement.

The heart is the perfection of the whole organism. Therefore the principles of the power of perception and the souls ability to nourish itself must lie in the heart.