In the case of some people, not even if we had the most accurate scientific knowledge, would it be easy to persuade them were we to address them through the medium of that knowledge; for a scientific discourse, it is the privilege of education to appreciate, and it is impossible that this should extend to the multitude.
Moral virtue is ... a mean between two vices, that of excess and that of defect, and ... it is no small task to hit the mean in each case, as it is not, for example, any chance comer, but only the geometer, who can find the center of a given circle.
First, have a definite, clear practical ideal; a goal, an objective. Second, have the necessary means to achieve your ends; wisdom, money, materials, and methods. Third, adjust all your means to that end.
Of ill-temper there are three kinds: irascibility, bitterness, sullenness. It belongs to the ill-tempered man to be unable to bear either small slights or defeats but to be given to retaliation and revenge, and easily moved to anger by any chance deed or word. Ill-temper is accompanied by excitability of character, instability, bitter speech, and liability to take offence at trifles and to feel these feelings quickly and on slight occasions.
The line has magnitude in one way, the plane in two ways, and the solid in three ways, and beyond these there is no other magnitude because the three are all.