Immanuel Kant on Philosophy

"Dare to know!"

"Two things awe me most: the starry sky above me and the moral law within me."

"Is it reasonable to assume a purposiveness in all the parts of nature and to deny it to the whole?"

"...happiness is not an ideal of reason but of imagination, resting solely on empirical grounds."

"The concept of space is not abstracted from external sensations."

"Philosophical knowledge is the knowledge gained by reason from concepts; mathematical knowledge is the knowledge gained by reason from the construction of concepts."

"The public use of a man's reason must be free at all times, and this alone can bring enlightenment among men..."

"It is precisely in knowing its limits that philosophy consists."

"For it is extremely absurd to expect to be enlightened by reason, and yet to prescribe to her beforehand on which side she must incline."

"In man those natural capacities which are directed to the use of his reason are to be fully developed only in the race, not in the individual."

"# Political independence, as the right to owe his existence and continuance in society not to the arbitrary will of another, but to his own rights and powers as a member of the commonwealth."

"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?"

"The universal and lasting establishment of peace constitutes not merely a part, but the whole final purpose and end of the science of right as viewed within the limits of reason."

"Human reason is by nature architectonic."

"I freely admit that the remembrance of David Hume was the very thing that many years ago first interrupted my dogmatic slumber and gave a completely different direction to my researches in the field of speculative philosophy."

"I maintain that in every special natural doctrine only so much science proper is to be met with as mathematics; for... science proper, especially of nature, requires a pure portion, lying at the foundation of the empirical, and based upon à priori knowledge of natural things. ...the conception should be constructed. But the cognition of the reason through construction of conceptions is mathematical. A pure philosophy of nature in general, namely, one that only investigates what constitutes a nature in general, may thus be possible without mathematics; but a pure doctrine of nature respecting determinate natural things , is only possible by means of mathematics; and as in every natural doctrine only so much science proper is to be met with therein as there is cognition à priori, a doctrine of nature can only contain so much science proper as there is in it of applied mathematics."

"I do not, therefore, need any penetrating acuteness to see what I have to do in order that my volition be morally good. Inexperienced in the course of the world, incapable of being prepared for whatever might come to pass in it, I ask myself only: can you also will that your maxim become a universal law?"

"A metaphysics of morals is therefore indispensably necessary, not merely because of a motive to speculation — for investigating the source of the practical basic principles that lie a priori in our reason — but also because morals themselves remain subject to all sorts of corruption as long as we are without that clue and supreme norm by which to appraise them correctly..."

"It is absurd to excite reason against the primary postulates of pure time, as, for example, continuity, etc., since they follow from laws prior and superior to which nothing is found, and since reason herself in the use of the principle of contradiction cannot dispense with the support of this concept, so primitive and original is it."

"o require that a so-called layman should not use his own reason in religious matters, particularly since religion is to be appreciated as moral, but instead follow the appointed clergyman and thus someone else's reason, is an unjust demand because as to morals every man must account for all his doings. The clergyman will not and even cannot assume such a responsibility."

"The sham cause in physical influence consists in rashly assuming that the commerce of substance and transitive forces is sufficiently knowable from their mere existence. Hence it is not so much a system as rather the neglect of all philosophical system as a superfluity in the argument. Freeing the concept from this defect, we shall have a species of commerce alone deserving to be called real, and from which the whole constituting the world merits being called real, and not ideal or imaginary."

"The second is the partiality for unity proper to the philosophical mind, whence this wide-spread canon has flown forth: principles are not to be multiplied beyond supreme necessity, to which we give in our adhesion, not because we have insight into causal unity in the world either by reason or experience, but as seeking it by an impulse of the intellect which seems to itself to have by thus much advanced in the explication of phenomena, by as much as it is granted to it to descend from the same principle to a greater number of consequences,"

"In the metaphysical elements of aesthetics the various nonmoral feelings are to be made use of; in the elements of moral metaphysics the various moral feelings of men, according to the differences in sex, age, education, and government, of races and climates, are to be employed."

"Nature has willed that man should, by himself, produce everything that goes beyond the mechanical ordering of his animal existence, and that he should partake of no other happiness or perfection than that which he himself, independently of instinct, has created by his own reason."

"Nature, therefore, is subject with absolute precision to all the precepts of geometry as to all the properties of space there demonstrated, this being the subjective condition, not hypothetically but intuitively given, of every phenomenon in which nature can ever be revealed to the senses."

"When the man governed by self-interest, the god of this world, does not renounce it but merely refines it by the use of reason and extends it beyond the constricting boundary of the present, he is represented as one who, in his very person , defrauds his master and wins from him sacrifices in behalf of “duty."

"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."

"Tibet... this is the highest country. No doubt it was inhabited before any other and could even have been the site of all creation and all science. The culture of the Indians, as is known is almost certainly came from Tibet, just as all our arts like agriculture, numbers, the game of chess, etc., seem to have come from India."

"Newton... says: geometry is proud of being able to achieve so much while taking so little from extraneous sources. One might say of metaphysics, on the other hand: it stands astonished, that with so much offered it by pure mathematics it can effect so little. In the meantime, this little is something which mathematics indispensably requires in its application to natural science, which, inasmuch as it must here necessarily borrow from metaphysics, need not be ashamed to allow itself to be seen in company with the latter."

"Even if there never have been actions arising from such pure sources, what is at issue here is not whether this or that happened; that, instead, reason by itself and independently of all appearances commands what ought to happen; that, accordingly, actions of which the world has perhaps so far given no example, and whose very practicability might be very much doubted by one who bases everything on experience, are still inflexibly commanded by reason … because … duty … lies, prior to all experience, in the idea of a reason determing the will by means of apriori grounds."