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must be opposed on subjective grounds, while the possibility of this

being in itself cannot with justice be denied); or, both propositions,

being dialectical in their nature, are based upon an impossible

conception. In this latter case the rule applies: non entis nulla sunt

predicata; that is to say, what we affirm and what we deny, respecting

such an object, are equally untrue, and the apagogic mode of

arriving at the truth is in this case impossible. If, for example,

we presuppose that the world of sense is given in itself in its

totality, it is false, either that it is infinite, or that it is

finite and limited in space. Both are false, because the hypothesis is

false. For the notion of phenomena (as mere representations) which are

given in themselves (as objects) is self-contradictory; and the

infinitude of this imaginary whole would, indeed, be unconditioned,

but would be inconsistent (as everything in the phenomenal world is

conditioned) with the unconditioned determination and finitude of

quantities which is presupposed in our conception.

The apagogic mode of proof is the true source of those illusions

which have always had so strong an attraction for the admirers of

dogmatical philosophy. It may be compared to a champion who

maintains the honour and claims of the party he has adopted by

offering battle to all who doubt the validity of these claims and

the purity of that honour; while nothing can be proved in this way,

except the respective strength of the combatants, and the advantage,

in this respect, is always on the side of the attacking party.

Spectators, observing that each party is alternately conqueror and

conquered, are led to regard the subject of dispute as beyond the

power of man to decide upon. But such an opinion cannot be

justified; and it is sufficient to apply to these reasoners the

remark:

Non defensoribus istis

Tempus eget.

Each must try to establish his assertions by a transcendental

deduction of the grounds of proof employed in his argument, and thus

enable us to see in what way the claims of reason may be supported. If

an opponent bases his assertions upon subjective grounds, he may be

refuted with ease; not, however to the advantage of the dogmatist, who

likewise depends upon subjective sources of cognition and is in like

manner driven into a corner by his opponent. But, if parties employ

the direct method of procedure, they will soon discover the

difficulty, nay, the impossibility of proving their assertions, and

will be forced to appeal to prescription and precedence; or they will,

by the help of criticism, discover with ease the dogmatical

illusions by which they had been mocked, and compel reason to renounce

its exaggerated pretensions to speculative insight and to confine

itself within the limits of its proper sphere- that of practical

principles.

CHAPTER II. The Canon of Pure Reason.

It is a humiliating consideration for human reason that it is

incompetent to discover truth by means of pure speculation, but, on

the contrary, stands in need of discipline to check its deviations

from the straight path and to expose the illusions which it

originates. But, on the other hand, this consideration ought to

elevate and to give it confidence, for this discipline is exercised by

itself alone, and it is subject to the censure of no other power.

The bounds, moreover, which it is forced to set to its speculative

exercise, form likewise a check upon the fallacious pretensions of

opponents; and thus what remains of its possessions, after these

exaggerated claims have been disallowed, is secure from attack or

usurpation. The greatest, and perhaps the only, use of all

philosophy of pure reason is, accordingly, of a purely negative

character. It is not an organon for the extension, but a discipline

for the determination, of the limits of its exercise; and without

laying claim to the discovery of new truth, it has the modest merit of

guarding against error.

At the same time, there must be some source of positive cognitions

which belong to the domain of pure reason and which become the

causes of error only from our mistaking their true character, while

they form the goal towards which reason continually strives. How

else can we account for the inextinguishable desire in the human

mind to find a firm footing in some region beyond the limits of the

world of experience? It hopes to attain to the possession of a

knowledge in which it has the deepest interest. It enters upon the

path of pure speculation; but in vain. We have some reason, however,

to expect that, in the only other way that lies open to it- the path

of practical reason- it may meet with better success.

I understand by a canon a list of the a priori principles of the

proper employment of certain faculties of cognition. Thus general

logic, in its analytical department, is a formal canon for the

faculties of understanding and reason. In the same way, Transcendental

Analytic was seen to be a canon of the pure understanding; for it

alone is competent to enounce true a priori synthetical cognitions.

But, when no proper employment of a faculty of cognition is

possible, no canon can exist. But the synthetical cognition of pure

speculative reason is, as has been shown, completely impossible. There

cannot, therefore, exist any canon for the speculative exercise of

this faculty- for its speculative exercise is entirely dialectical;

and, consequently, transcendental logic, in this respect, is merely

a discipline, and not a canon. If, then, there is any proper mode of

employing the faculty of pure reason- in which case there must be a

canon for this faculty- this canon will relate, not to the

speculative, but to the practical use of reason. This canon we now

proceed to investigate.

SECTION I. Of the Ultimate End of the Pure Use of Reason.

There exists in the faculty of reason a natural desire to venture

beyond the field of experience, to attempt to reach the utmost

bounds of all cognition by the help of ideas alone, and not to rest

satisfied until it has fulfilled its course and raised the sum of

its cognitions into a self-subsistent systematic whole. Is the

motive for this endeavour to be found in its speculative, or in its

practical interests alone?

Setting aside, at present, the results of the labours of pure reason

in its speculative exercise, I shall merely inquire regarding the

problems the solution of which forms its ultimate aim, whether reached

or not, and in relation to which all other aims are but partial and

intermediate. These highest aims must, from the nature of reason,

possess complete unity; otherwise the highest interest of humanity

could not be successfully promoted.

The transcendental speculation of reason relates to three things:

the freedom of the will, the immortality of the soul, and the

existence of God. The speculative interest which reason has in those

questions is very small; and, for its sake alone, we should not

undertake the labour of transcendental investigation- a labour full of

toil and ceaseless struggle. We should be loth to undertake this

labour, because the discoveries we might make would not be of the

smallest use in the sphere of concrete or physical investigation. We

may find out that the will is free, but this knowledge only relates to

the intelligible cause of our volition. As regards the phenomena or

expressions of this will, that is, our actions, we are bound, in

obedience to an inviolable maxim, without which reason cannot be

employed in the sphere of experience, to explain these in the same way

as we explain all the other phenomena of nature, that is to say,

according to its unchangeable laws. We may have discovered the

spirituality and immortality of the soul, but we cannot employ this

knowledge to explain the phenomena of this life, nor the peculiar

nature of the future, because our conception of an incorporeal

nature is purely negative and does not add anything to our

knowledge, and the only inferences to be drawn from it are purely

fictitious. If, again, we prove the existence of a supreme

intelligence, we should be able from it to make the conformity to aims

existing in the arrangement of the world comprehensible; but we should

not be justified in deducing from it any particular arrangement or

disposition, or inferring any where it is not perceived. For it is a

necessary rule of the speculative use of reason that we must not

overlook natural causes, or refuse to listen to the teaching of

experience, for the sake of deducing what we know and perceive from

something that transcends all our knowledge. In one word, these

three propositions are, for the speculative reason, always

transcendent, and cannot be employed as immanent principles in

relation to the objects of experience; they are, consequently, of no

use to us in this sphere, being but the valueless results of the

severe but unprofitable efforts of reason.

If, then, the actual cognition of these three cardinal

propositions is perfectly useless, while Reason uses her utmost

endeavours to induce us to admit them, it is plain that their real

value and importance relate to our practical, and not to our

speculative interest.

I term all that is possible through free will, practical. But if the

conditions of the exercise of free volition are empirical, reason

can have only a regulative, and not a constitutive, influence upon it,

and is serviceable merely for the introduction of unity into its

empirical laws. In the moral philosophy of prudence, for example,

the sole business of reason is to bring about a union of all the ends,

which are aimed at by our inclinations, into one ultimate end- that of

happiness- and to show the agreement which should exist among the

means of attaining that end. In this sphere, accordingly, reason

cannot present to us any other than pragmatical laws of free action,

for our guidance towards the aims set up by the senses, and is

incompetent to give us laws which are pure and determined completely a

priori. On the other hand, pure practical laws, the ends of which have

been given by reason entirely a priori, and which are not

empirically conditioned, but are, on the contrary, absolutely

imperative in their nature, would be products of pure reason. Such are

the moral laws; and these alone belong to the sphere of the

practical exercise of reason, and admit of a canon.

All the powers of reason, in the sphere of what may be termed pure

philosophy, are, in fact, directed to the three above-mentioned

problems alone. These again have a still higher end- the answer to the

question, what we ought to do, if the will is free, if there is a

God and a future world. Now, as this problem relates to our in

reference to the highest aim of humanity, it is evident that the

ultimate intention of nature, in the constitution of our reason, has

been directed to the moral alone.

We must take care, however, in turning our attention to an object

which is foreign* to the sphere of transcendental philosophy, not to

injure the unity of our system by digressions, nor, on the other hand,

to fail in clearness, by saying too little on the new subject of

discussion. I hope to avoid both extremes, by keeping as close as

possible to the transcendental, and excluding all psychological,

that is, empirical, elements.

*All practical conceptions relate to objects of pleasure and pain,

and consequently- in an indirect manner, at least- to objects of

feeling. But as feeling is not a faculty of representation, but lies

out of the sphere of our powers of cognition, the elements of our

judgements, in so far as they relate to pleasure or pain, that is, the

elements of our practical judgements, do not belong to

transcendental philosophy, which has to do with pure a priori

cognitions alone.

I have to remark, in the first place, that at present I treat of the

conception of freedom in the practical sense only, and set aside the

corresponding transcendental conception, which cannot be employed as a

ground of explanation in the phenomenal world, but is itself a problem

for pure reason. A will is purely animal (arbitrium brutum) when it is

determined by sensuous impulses or instincts only, that is, when it is

determined in a pathological manner. A will, which can be determined

independently of sensuous impulses, consequently by motives

presented by reason alone, is called a free will (arbitrium

liberum); and everything which is connected with this free will,

either as principle or consequence, is termed practical. The existence

of practical freedom can be proved from experience alone. For the

human will is not determined by that alone which immediately affects

the senses; on the contrary, we have the power, by calling up the

notion of what is useful or hurtful in a more distant relation, of

overcoming the immediate impressions on our sensuous faculty of

desire. But these considerations of what is desirable in relation to

our whole state, that is, is in the end good and useful, are based

entirely upon reason. This faculty, accordingly, enounces laws,

which are imperative or objective laws of freedom and which tell us

what ought to take place, thus distinguishing themselves from the laws

of nature, which relate to that which does take place. The laws of

freedom or of free will are hence termed practical laws.

Whether reason is not itself, in the actual delivery of these

laws, determined in its turn by other influences, and whether the

action which, in relation to sensuous impulses, we call free, may not,

in relation to higher and more remote operative causes, really form

a part of nature- these are questions which do not here concern us.

They are purely speculative questions; and all we have to do, in the

practical sphere, is to inquire into the rule of conduct which

reason has to present. Experience demonstrates to us the existence

of practical freedom as one of the causes which exist in nature,

that is, it shows the causal power of reason in the determination of

the will. The idea of transcendental freedom, on the contrary,