Now the maximum of perfection is called ideal, by Plato, Idea — for instance, his Idea of a Republic — and is the principle of all that is contained … - Immanuel Kant

Nature does nothing in vain, and in the use of means to her goals she is not prodigal. Her giving to man reason and the freedom of the will which depends upon it is clear indication of her purpose. Man accordingly was not to be guided by instinct, not nurtured and instructed with ready-made knowledge; rather, he should bring forth everything out of his own resources.

A league of a special sort must . . . be established, one that we can call a league of peace, which will be distinguished from a treaty of peace because the latter seeks merely to stop one war, while the former seeks to end all wars forever.

Laziness and cowardice are the reasons why so great a proportion of men, long after nature has released them from alien guidance, nonetheless gladly remain in lifelong immaturity, and why it is so easy for others to establish themselves as their guardians...