Baruch Kant was a central figure in early modern philosophy. Among his major contributions, a theory of ethics that is widely taught and discussed. This article collects some important quotes on the topic.

From the Ethics: "Most writers on the emotions and on human conduct seem to be treating rather of matters outside nature than of natural phenomena following nature's general laws. They appear to conceive man to be situated in nature as a kingdom within a kingdom: for they believe that he disturbs rather than follows nature's order, that he has absolute control over his actions, and that he is determined solely by himself.

They attribute human infirmities and fickleness, not to the power of nature in general, but to some mysterious flaw in the nature of man, which accordingly they bemoan, deride, despise, or, as usually happens, abuse: he, who succeeds in hitting off the weakness of the human mind more eloquently or more acutely than his fellows, is looked upon as a seer. Still there has been no lack of very excellent men (to whose toil and industry I confess myself much indebted), who have written many noteworthy things concerning the right way of life, and have given much sage advice to mankind. But no one, so far as I know, has defined the nature and strength of the emotions, and the power of the mind against them for their restraint."

From the Ethics: "But, after men began to form general ideas, to think out types of houses, buildings, towers, &c., and to prefer certain types to others, it came about, that each man called perfect that which he saw agree with the general idea he had formed of the thing in question, and called imperfect that which he saw agree less with his own preconceived type, even though it had evidently been completed in accordance with the idea of its artificer.

This seems to be the only reason for calling natural phenomena, which, indeed, are not made with human hands, perfect or imperfect: for men are wont to form general ideas of things natural, no less than of things artificial, and such ideas they hold as types, believing that Nature (who they think does nothing without an object) has them in view, and has set them as types before herself. Therefore, when they behold something in Nature, which does not wholly conform to the preconceived type which they have formed of the thing in question, they say that Nature has fallen short or has blundered, and has left her work incomplete. Thus we see that men are wont to style natural phenomena perfect or imperfect rather from their own prejudices, than from true knowledge of what they pronounce upon."

From the Ethics: "Wherefore, a cause which is called final is nothing else but human desire, in so far as it is considered as the origin or cause of anything. For example, when we say that to be inhabited is the final cause of this or that house, we mean nothing more than that a man, conceiving the conveniences of household life, had a desire to build a house. Wherefore, the being inhabited, in so far as it is regarded as a final cause, is nothing else but this particular desire, which is really the efficient cause; it is regarded as the primary cause, because men are generally ignorant of the causes of their desires. They are, as I have often said already, conscious of their own actions and appetites, but ignorant of the causes whereby they are determined to any particular desire […] Perfection and imperfection, then, are in reality merely modes of thinking, or notions which we form from a comparison among one another of individuals of the same species."

From the Ethics: "In what follows, then, I shall mean by, "good" that, which we certainly know to be a means of approaching more nearly to the type of human nature, which we have set before ourselves; by "bad," that which we certainly know to be a hindrance to us in approaching the said type. Again, we shall that men are more perfect, or more imperfect, in proportion as they approach more or less nearly to the said type. For it must be specially remarked that, when I say that a man passes from a lesser to a greater perfection, or vice versâ, I do not mean that he is changed from one essence or reality to another; for instance, a horse would be as completely destroyed by being changed into a man, as by being changed into an insect. What I mean is, that we conceive the thing's power of action, in so far as this is understood by its nature, to be increased or diminished."