Through laziness and cowardice a large part of mankind, even after nature has freed them from alien guidance, gladly remain immature. It is because of laziness and cowardice that it is so easy for others to usurp the role of guardians. It is so comfortable to be a minor!
The desire which a man has for a woman is not directed towards her because she is a human being, but because she is a woman ; that she is a human being is of no concern to the man; only her sex is the object of his desires.
Our knowledge springs from two fundamental sources of the mind; the first is the capacity of receiving representations (receptivity for impressions), the second is the power of knowing an object through these representations (spontaneity [in the production] of concepts).
I learned to honor human beings, and I would find myself far more useless than the common laborer if I did not believe that this consideration could impart to all others a value establishing the rights of humanity.
This can never become popular, and, indeed, has no occasion to be so; for fine-spun arguments in favour of useful truths make just as little impression on the public mind as the equally subtle objections brought against these truths. On the other hand, since both inevitably force themselves on every man who rises to the height of speculation, it becomes the manifest duty of the schools to enter upon a thorough investigation of the rights of speculative reason, and thus to prevent the scandal which metaphysical controversies are sure, sooner or later, to cause even to the masses.
Beneficence is a duty; and he who frequently practices it, and sees his benevolent intentions realized comes, at length, really to love him to whom he has done good.
If we knew that god exists, such knowledge would make morality impossible. For, if we acted morally from fear or fright, or confident of a reward, then this would not be moral. It would be enlightened selfishness.
The greatest problem for the human species, the solution of which nature compels him to seek, is that of attaining a civil society which can administer justice universally.
The infinitude of creation is great enough to make a world, or a Milky Way of worlds, look in comparison with it what a flower or an insect does in comparison with the Earth.
cruelty to animals is contrary to man's duty to himself, because it deadens in him the feeling of sympathy for their sufferings, and thus a natural tendency that is very useful to morality in relation to other human beings is weakened.
To a high degree we are, through art and science, cultured. We are civilized - perhaps too much for our own good - in all sorts of social grace and decorum. But to consider ourselves as
having reached morality - for that, much is lacking.