What we know is not capable of being otherwise; of things capable of being otherwise we do not know, when they have passed outsideour observation, whether they exist or not. Therefore the object of knowledge is of necessity. Therefore it is eternal; for things that are of necessity in the unqualified sense are all eternal; and things that are eternal are ungenerated and imperishable.

If everything when it occupies an equal space is at rest, and if that which is in locomotion is always occupying such a space at any moment, the flying arrow is therefore motionless.

Courage is the first of human qualities because it is the quality which guarantees the others.

He is courageous who endures and fears the right thing, for the right motive, in the right way and at the right times.

If liberty and equality, as is thought by some, are chiefly to be found in democracy, they will be best attained when all persons alike share in government to the utmost.

To the size of the state there is a limit, as there is to plants, animals and implements, for none of these retain their facility when they are too large.

Tragedy is an imitation not only of a complete action, but of events inspiring fear and pity. Such an effect is best produced when the events come on us by surprise; and the effect is heightened when, at the same time, they follow as cause and effect. The tragic wonder will then be great than if they happened of themselves or by accident; for even coincidences are most striking when they have an air of design.