A speaker who is attempting to move people to thought or action must concern himself with Pathos.

Why is it that all men who are outstanding in philosophy, poetry or the arts are melancholic?

Conscientious and careful physicians allocate causes of disease to natural laws, while the ablest scientists go back to medicine for their first principles.

When a draco has eaten much fruit, it seeks the juice of the bitter lettuce; it has been seen to do this.

Perception starts with the eye.

In justice is all virtues found in sum.

The more you know, the more you know you don't know.