Things which we see are not by themselves what we see ... It remains completely unknown to us what the objects may be by themselves and apart from the receptivity of our senses. We know nothing but our manner of perceiving them.
The instruction of children should aim gradually to combine knowing and doing. Among all sciences mathematics seems to be the only one of a kind to satisfy this aim most completely.
All trades, arts, and handiworks have gained by division of labor... Where the different kinds of work are not distinguished and divided, where everyone is a jack-of-all-trades, there manufactures remain still in the greatest barbarism.
Human freedom is realised in the adoption of humanity as an end in itself, for the one thing that no-one can be compelled to do by another is to adopt a particular end. - 'Metaphysical Principles of Virtue
Enlightenment is the liberation of man from his self-caused state of minority... Supere aude! Dare to use your own understanding!is thus the motto of the Enlightenment.
Often war is waged only in order to show valor; thus an inner dignity is ascribed to war itself, and even some philosophers have praised it as an ennoblement of humanity, forgetting the pronouncement of the Greek who said, 'War is an evil in as much as it produces more wicked men than it takes away.'
When a thoughtful human being has overcome incentives to vice and is aware of having done his bitter duty, he finds himself in a state that could be called happiness, a state of contentment and peace of mind in which virtue is its own reward.
Two things fill the mind with ever new and increasing admiration and awe, the oftener and more steadily we reflect on them: the starry heavens above and the moral law within.
Laziness and cowardice explain why so many men. . . remain under a life-long tutelage and why it is so easy for some men to set themselves up as the guardians of all the rest. . . If I have a book which understands for me, a pastor who has a conscience for me, a doctor who decides my diet, I need not trouble myself. If I am willing to pay, I need not think. Others will do it for me.
There will always be some people who think for themselves, even among the self-appointed guardians of the great mass who, after having thrown off the yoke of immaturity themselves, will spread about them the spirit of a reasonable estimate of their own value and of the need for every man to think for himself.
Every man is to be respected as an absolute end in himself; and it is a crime against the dignity that belongs to him as a human being, to use him as a mere means for some external purpose.
Thoughts without content are empty, intuitions without concepts are blind... The understanding can intuit nothing, the senses can think nothing. Only through their union can knowledge arise.