As the analysis of a substantial composite terminates only in a part which is not a whole, that is, in a simple part, so synthesis terminates only in a whole which is not a part, that is, the world.

The use of the intellect in the sciences whose primitive concepts as well as axioms are given by sensuous intuition is only logical, that is, by it we only subordinate cognitions to one another according to their relative universality conformably to the principle of contradiction, phenomena to more general phenomena, and consequences of pure intuition to intuitive axioms. But in pure philosophy, such as metaphysics, in which the use of the intellect in respect to principles is real, that is to say, where the primary concept of things and relations and the very axioms are given originally by the pure intellect itself, and not being intuitions do not enjoy immunity from error, the method precedes the whole science, and whatever is attempted before its precepts are thoroughly discussed and firmly established is looked upon as rashly conceived and to be rejected among vain instances of mental playfulness.

The method of the science not being practiced much nowadays, except what logic prescribes to all sciences generally, that fitted for the peculiar nature of metaphysics being simply ignored, it is no wonder that those who everlastingly turn the Sisyphean stone of this inquiry do not seem so far to have made much progress. Though here I neither can nor will expatiate upon so important and extensive a subject, I shall briefly shadow forth what constitutes no despicable part of this method, namely, the infection between sensuous and intellectual cognition, not only as creeping in on those incautious in the application of principles, but even producing spurious principles under the appearance of axioms.

A spurious axiom of the first class is: Whatever is, is somewhere and sometime.

In man (as the only rational creature on earth) 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.

Nature does nothing in vain, and in the use of means to her goals she is not prodigal. Her giving to man reason and the freedom of the will which depends upon it is clear indication of her purpose. Man accordingly was not to be guided by instinct, not nurtured and instructed with ready-made knowledge; rather, he should bring forth everything out of his own resources.

The means employed by Nature to bring about the development of all the capacities of men is their antagonism in society, so far as this is, in the end, the cause of a lawful order among men.

The greatest problem for the human race, to the solution of which Nature drives man, is the achievement of a universal civic society which administers law among men.

The problem of establishing a perfect civic constitution is dependent upon the problem of a lawful external relation among states and cannot be solved without a solution of the latter problem.

All wars are accordingly so many attempts (not in the intention of man, but in the intention of Nature) to establish new relations among states, and through the destruction or at least the dismemberment of all of them to create new political bodies, which, again, either internally or externally, cannot maintain themselves and which must thus suffer like revolutions; until finally, through the best possible civic constitution and common agreement and legislation in external affairs, a state is created which, like a civic commonwealth, can maintain itself automatically.

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

The history of mankind can be seen, in the large, as the realization of Nature's secret plan to bring forth a perfectly constituted state as the only condition in which the capacities of mankind can be fully developed, and also bring forth that external relation among states which is perfectly adequate to this end.

A philosophical attempt to work out a universal history according to a natural plan directed to achieving the civic union of the human race must be regarded as possible and, indeed, as contributing to this end of Nature.

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...

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?

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.

Morality is thus the relation of actions to the autonomy of the will, that is, to a possible giving of universal law through its maxims. An action that can coexist with the autonomy of the will is permitted; one that does not accord with it is forbidden. A will whose maxims necessarily harmonize with the laws of autonomy is a holy, absolutely good will. The dependence upon the principle of autonomy of a will that is not absolutely good (moral necessitation) is obligation. This, accordingly, cannot be attributed to a holy being. The objective of an action from obligation is called duty.

... happiness is not an ideal of reason, but of imagination, resting on merely empirical grounds…

All natural capacities of a creature are destined to evolve completely to their natural end. First Thesis Variant translations: All natural capacities of a creature are destined sooner or later to be developed completely and in conformity with their end. All natural capacities of a creature are destined to develop themselves completely and to their purpose.

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.

Since men in their endeavors behave, on the whole, not just instinctively, like the brutes, nor yet like rational citizens of the world according to some agreed-on plan, no history of man conceived according to a plan seems to be possible, as it might be possible to have such a history of bees or beavers. One cannot suppress a certain indignation when one sees men's actions on the great world-stage and finds, beside the wisdom that appears here and there among individuals, everything in the large woven together from folly, childish vanity, even from childish malice and destructiveness. In the end, one does not know what to think of the human race, so conceited in its gifts.

...they cudgel their brains with absurd questions, such as, for instance, why God did not make the world many centuries earlier. They persuade themselves that it is easy to conceive, to be sure, how God may discern what is present, that is, what is actual in the time in which he is, but how He may foresee what is future, that is, what is actual in the time in which He is not yet, they deem an intellectual difficulty; as if the existence of the Necessary Being descended through all the moments of an imaginary time, and, having already exhausted a part of His duration, saw before Him the eternity He was yet to live simultaneously with the present events of the world. All these difficulties upon proper insight into the notion of time vanish like smoke.

The prejudices of the second species, since they impose upon the intellect by the sensual conditions restricting the mind if it wishes in certain cases to attain to what is intellectual, lurk more deeply. One of them is that which affects knowledge of quantity, the other that affecting knowledge of qualities generally. The former is: every actual multiplicity can be given numerically, and hence, every infinite quantity; the latter, whatever is impossible contradicts itself. In either of them the concept of time, it is true, does not enter into the very notion of the predicate, nor is it attributed as a qualification to the subject. But yet it serves as a means for forming an idea of the predicate, and thus, being a condition, affects the intellectual concept of the subject to the extent that the latter is only attained by its aid.

The spurious axioms of the third kind from conditions proper to the subject whence they are transferred rashly to the object are plentiful, not, as in those of the Second Class, because the only way to the intellectual concept lies through the sensuous data, but because only by aid of the latter can the concept be applied to that which is given by experience, that is, can we know whether something is contained under a certain intellectual concept or not. To this class belongs the threadbare one of the schools: whatever exists contingently does at some time not exist. This spurious principle springs from the poverty of the intellect, having insight frequently into the nominal, rarely into the real, marks of contingency or necessity.

To these spurious principles must be added some others of great affinity with them... First, that by which we assume that everything in the universe is done according to the order of nature, which principle by Epicurus was proclaimed without any restriction, and by all other philosophers unanimously with extremely rare exceptions, not to be admitted but from supreme necessity.

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,

The third of this kind of principles is : matter neither originates nor perishes; all the changes in the world concern form only ; a postulate which on the recommendation of common sense has spread through all philosophical schools, not because it is to be taken as having been found so, or as having been demonstrated by arguments a priori, but because if we were to admit that matter itself is fleeting and transitory, nothing at all that is stable and lasting would be left any longer to serve for the explication of phenomena according to universal and perpetual laws, and hence nothing at all would be left for the exercise of the intellect.

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.

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 guardians who have kindly undertaken the supervision will see to it that by far the largest part of mankind, including the entire "beautiful sex," should consider the step into maturity, not only as difficult but as very dangerous. After having made their domestic animals dumb and having carefully prevented these quiet creatures from daring to take any step beyond the lead-strings to which they have fastened them, these guardians then show them the danger which threatens them, should they attempt to walk alone.

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.

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.

A public can only arrive at enlightenment slowly. Through revolution, the abandonment of personal despotism may be engendered and the end of profit-seeking and domineering oppression may occur, but never a true reform of the state of mind. Instead, new prejudices, just like the old ones, will serve as the guiding reins of the great, unthinking mass. All that is required for this enlightenment is freedom; and particularly the least harmful of all that may be called freedom, namely, the freedom for man to make public use of his reason in all matters. But I hear people clamor on all sides: Don't argue! The officer says: Don't argue, drill! The tax collector: Don't argue, pay! The pastor: Don't argue, believe!

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

Whatever concept one may hold, from a metaphysical point of view, concerning the freedom of the will, certainly its appearances, which are human actions, like every other natural event are determined by universal laws. However obscure their causes, history, which is concerned with narrating these appearances, permits us to hope that if we attend to the play of freedom of the human will in the large, we may be able to discern a regular movement in it, and that what seems complex and chaotic in the single individual may be seen from the standpoint of the human race as a whole to be a steady and progressive though slow evolution of its original endowment.

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 (corporeal doctrine and mental doctrine), 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.