One who makes himself a worm cannot complain afterwards if people step on him.
Two things fill the mind with ever-increasing wonder and awe, the more often and the more intensely the mind of thought is drawn to them: the starry heavens above me and the moral law within me.
Thoughts without content are empty, intuitions without concepts are blind.
Act only according to that maxim whereby you can at the same time will that it should become a universal law.
But only he who, himself enlightened, is not afraid of shadows.
Without man and his potential for moral progress, the whole of reality would be a mere wilderness, a thing in vain, and have no final purpose.
Settle, for sure and universally, what conduct will promote the happiness of a rational being.
El sabio puede cambiar de opinión. El necio, nunca.
I had to deny knowledge in order to make room for faith.
All our knowledge begins with the senses, proceeds then to the understanding, and ends with reason. There is nothing higher than reason.
He who would know the world must first manufacture it.
Philosophical knowledge is knowledge which reason gains from concepts mathematical knowledge is knowledge which reason gains from the construction of concepts.
Science is organized knowledge. Wisdom is organized life
…[H]uman reason in its pure use, so long as it was not critically examined, has first tried all possible wrong ways before it succeeded in finding the one true way.
Treat people as an end, and never as a means to an end
In every department of physical science there is only so much science, properly so-called, as there is mathematics.
…[P]hysics… [is] the philosophy of nature, so far as it is based on empirical laws.
Seek not the favor of the multitude; it is seldom got by honest and lawful means. But seek the testimony of few; and number not voices, but weigh them.
…[F]reedom… is a property of all rational beings.
Freedom is alone the unoriginated birthright of man, and belongs to him by force of his humanity; and is independent of the will and co-action of every other…
The enjoyment of power inevitably corrupts the judgement of reason, and perverts its liberty.
In all judgements by which we describe anything as beautiful, we allow no one to be of another opinion.
Act in such a way that you treat humanity, whether in your own person or in the person of any other, never merely as a means to an end, but always at the same time as an end.
Out of the crooked timber of humanity, no straight thing was ever made.
From the crooked timber of humanity, a straight board cannot be hewn.
The touchstone of everything that can be concluded as a law for a people lies in the question whether the people could have imposed such a law on itself.
Give me matter, and I will construct a world out of it!
I class the principle of moral feeling under that of happiness, because every empirical interest promises to contribute to our well-being by the agreeableness that a thing affords, whether profit be regarded.
We are not rich by what we possess but by what we can do without.
The schematicism by which our understanding deals with the phenomenal world … is a skill so deeply hidden in the human soul that we shall hardly guess the secret trick that Nature here employs.
An action, to have moral worth, must be done from duty.
But although all our knowledge begins with experience, it does not follow that it arises from experience.
Experience without theory is blind, but theory without experience is mere intellectual play.
But, though all our knowledge begins with experience, it by no means follows that all arises out of experience.
He who is cruel to animals becomes hard also in his dealings with men. We can judge the heart of a man by his treatment of animals.
The people naturally adhere most to doctrines which demand the least self-exertion and the least use of their own reason, and which can best accommodate their duties to their inclinations.
…[T]o be unfaithful to my maxim of prudence may often be very advantageous to me, although to abide by it is certainly safer.
If we were to suppose that mankind never can or will be in a better condition, it seems impossible to justify by any kind of theodicy the mere fact that such a race of corrupt beings could have been created on earth at all.
Only the descent into the hell of self-knowledge can pave the way to godliness.
Whereas the beautiful is limited, the sublime is limitless, so that the mind in the presence of the sublime, attempting to imagine what it cannot, has pain in the failure but pleasure in contemplating the immensity of the attempt
…I am never to act otherwise than so that I could also will that my maxim should become universal law.
Simply to acquiesce in skepticism can never suffice to overcome the restlessness of reason.
The will is conceived as a faculty of determining oneself to action in accordance with the conception of certain laws. And such a faculty can be found only in rational beings.
The whole interest of my reason, whether speculative or practical, is concentrated in the three following questions: What can I know? What should I do? What may I hope? (Critique of Pure Reason
Genius is the ability to independently arrive at and understand concepts that would normally have to be taught by another person.
The main point of enlightenment is man’s release from his self-caused immaturity, primarily in matters of religion.
…[W]e must admit that… law must be valid, not merely for men, but for all rational creatures generally, not merely under certain contingent conditions or with exceptions, but with absolute necessity…
Innocence is a splendid thing, only it has the misfortune not to keep very well and to be easily misled.
It is impossible to conceive anything at all in the world, or even out of it, which can be taken as good without qualification, except a good will.
…in its practical purpose the footpath of freedom is the only one on which it is possible to make use of reason in our conduct. Hence it is as impossible for the subtlest philosophy as for the commonest reasoning to argue freedom away.
The true religion is to be posited not in the knowledge or confession of what God allegedly does or has done for our salvation, but in what we must do to become worthy of this.
Human beings are never to be treated as a means but always as ends.
Laughter is an affect resulting from the sudden transformation of a heightened expectation into nothing.
Anarchy is law and freedom without force.Despotism is law and force without freedom.Barbarism force without freedom and law.Republicanism is force with freedom and law.
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.
The desire of a man for a woman is not directed at her because she is a human being but because she is a woman. That she is a human being is of no concern to him.
What can I know? What ought I to do? What can I hope?
All the interests of my reason, speculative as well as practical, combine in the three following questions: 1. What can I know? 2. What ought I to do? 3. What may I hope?
Even philosophers will praise war as ennobling mankind, forgetting the Greek who said: ‘War is bad in that it begets more evil than it kills.’
Morality is not the doctrine of how we may make ourselves happy, but how we may make ourselves worthy of happiness.
Happiness is not an ideal of reason, but of imagination.
It is not God’s will merely that we should be happy, but that we should make ourselves happy.
Immaturity is the incapacity to use one’s intelligence without the guidance of another.
Religion is the recognition of all our duties as divine commands.
It is beyond a doubt that all our knowledge begins with experience.
I had therefore to remove knowledge, in order to make room for belief.
Intuition and concepts constitute… the elements of all our knowledge, so that neither concepts without an intuition in some way corresponding to them, nor intuition without concepts, can yield knowledge.