Immanuel Kant

(22 April 1724 – 12 February 1804) German philosopher (a native of the Kingdom of Prussia) and one of the central Enlightenment thinkers.

The state of peace among men living side by side is not the natural state; the natural state is one of war. This does not always mean open hostilities, but at least an unceasing threat of war. A state of peace, therefore, must be established, for in order to be secured against hostility it is not sufficient that hostilities simply not be committed; and, until security is pledged to each by his neighbour (a thing that can only occur in a civil state) , each may treat his neighbour, from who he demands this security, as an enemy.
Religion is too important a matter to its devotees to be a subject of ridicule. If they indulge in absurdities, they are to be pitied rather than ridiculed.
We believe, or assume to believe, that we satisfy [our] duty to humanity if we first provide fully for our own material wants and then pay our tribute to the universal provider by giving a little to the poor. But if we were scrupulously just there would be no poor to whom we could give alms and think that we had realized the merit of benevolence. Better than charity, better than giving of our surplus is conscientious and scrupulously fair conduct and a helping hand in need.
The point is not always to speculate, but also ultimately to think about applying our knowledge. Today, however, he who lives in conformity with what he teaches is taken for a dreamer.
Dare to know!
What would proceed from a continual promotion of living force, which does not let itself climb above a certain grade, other than a rapid death from delight?
Prudence reproaches; conscience accuses.
Heaven has given human beings three things to balance the odds of life: hope, sleep, and laughter.
Despite the great wealth of words which European languages possess, the thinker finds himself often at a loss for an expression exactly suited to his conception, for want of which he is unable to make himself intelligible either to others or to himself. To coin new words is a pretension to legislation in language which is seldom successful; and, before recourse is taken to so desperate an expedient, it is advisable to examine the dead and learned languages, with the hope and the probability that we may there meet with some adequate expression of the notion we have in our minds. In this case, even if the original meaning of the word has become somewhat uncertain, from carelessness or want of caution on the part of the authors of it, it is always better to adhere to and confirm its proper meaning– even although it may be doubtful whether it was formerly used in exactly this sense– than to make our labour vain by want of sufficient care to render ourselves intelligible.
Morality is not the doctrine of how we may make ourselves happy, but how we may make ourselves worthy of happiness.
It is beyond doubt that all knowledge begins with experience.
From this it follows incontestably, that pure concepts of the understanding never admit of a transcendental, but only of an empirical use, and that the principles of the pure understanding can only be referred, as general conditions of a possible experience, to objects of the senses, never to things in themselves…
The possession of power inevitably spoils the free use of reason.
From such crooked timber as humanity is made of, no straight thing was ever constructed.
The enjoyment of power inevitably corrupts the judgement of reason, and perverts its liberty.
You must, therefore you can. A free will and a will subject to moral laws are one and the same thing.
However, one can also cognize the existence of the thing prior to the perception of it, and therefore cognize it comparatively a priori, if only it is connected with some perceptions in accordance with the principles of their empirical connection (the analogies). For in that case the existence of the thing is still connected with our perceptions in a possible experience, and with the guidance of the analogies we can get from our actual perceptions to the thing in the series of possible perceptions. Thus we cognize the existence of a magnetic matter penetrating all bodies from the perception of attracted iron filings, although an immediate perception of this matter is impossible for us given the construction of our organs. For in accordance with the laws of sensibility and the context of our perceptions we could also happen upon the immediate empirical intuition of it in an experience of if our senses, the crudeness of which does not affect the form of possible experience in general, were finer. Thus wherever perception and whatever is appended to it in accordance with empirical laws reaches, there too reaches our cognition of the existence of things. If we do not being with experience, or proceed in accordance with laws of the empirical connection of appearances, then we are only making a vain display of wanting to discover or research the existence of any thing.
The main point of enlightenment is man's release from his self-caused immaturity, primarily in matters of religion.
What can I know? What ought I to do? What can I hope?
By a lie a man throws away, and as it were, annihilates his dignity as a man.
No one may force anyone to be happy according to his manner of imagining the well-being of other men; instead, everyone may seek his happiness in the way that seems good to him as long as he does not infringe on the freedom of others to pursue a similar purpose, when such freedom may coexist with the freedom of every other man according to a possible and general law.
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...
Job says what he thinks and feels, and how every person would likely feel in his position. His friends, on the other hand, talk as if they were secretly being watched by the powerful Ruler whose case is open to their verdict, and as if, in making their verdict, they cared more about winning His favor than about the truth. This trickery of maintaining something just to keep up appearances, contrary to their true beliefs, feigning a conviction they did not have, stands in stark contrast to Job’s candor, which is so far removed from flattery that it borders on audacity, but nevertheless casts him in a very favorable light.
Act only according to that maxim by which you can at the same time will that it should become a universal law
Human reason goes forth inexorably to such questions as cannot be answered by any experiential use of reason or principles based on it.
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.
But, though all our knowledge begins with experience, it by no means follows that all arises out of experience.
Man desires concord; but nature know better what is good for his species; she desires discord.
Art is purposiveness without purpose.
It is difficult for the isolated individual to work himself out of the immaturity which has become almost natural for him. He has even become fond of it and for the time being is incapable of employing his own intelligence, because he has never been allowed to make the attempt. Statutes and formulas, these mechanical tools of a serviceable use, or rather misuse, of his natural faculties, are the ankle-chains of a continuous immaturity. Whoever threw it off would make an uncertain jump over the smallest trench because he is not accustomed to such free movement. Therefore there are only a few who have pursued a firm path and have succeeded in escaping from immaturity by their own cultivation of the mind.