This principle of reason is hence valid only as a rule for the extension of a possible experience- its invalidity as a principle constitutive of phenomena in themselves having been sufficiently demonstrated.And thus, too, the antinomial conflict of reason with itself is completely put an end to; inasmuch as we have not only presented a critical solution of the fallacy lurking in the opposite statements of reason, but have shown the true meaning of the ideas which gave rise to these statements.The dialectical principle of reason has, therefore, been changed into a doctrinal principle.But in fact, if this principle, in the subjective signification which we have shown to be its only true sense, may be guaranteed as a principle of the unceasing extension of the employment of our understanding, its influence and value are just as great as if it were an axiom for the a priori determination of objects.For such an axiom could not exert a stronger influence on the extension and rectification of our knowledge, otherwise than by procuring for the principles of the understanding the most widely expanded employment in the field of experience.
I.Solution of the Cosmological Idea of the Totality of the Composition of Phenomena in the Universe.
Here, as well as in the case of the other cosmological problems, the ground of the regulative principle of reason is the proposition that in our empirical regress no experience of an absolute limit, and consequently no experience of a condition, which is itself absolutely unconditioned, is discoverable.And the truth of this proposition itself rests upon the consideration that such an experience must represent to us phenomena as limited by nothing or the mere void, on which our continued regress by means of perception must abut- which is impossible.
Now this proposition, which declares that every condition attained in the empirical regress must itself be considered empirically conditioned, contains the rule in terminis, which requires me, to whatever extent I may have proceeded in the ascending series, always to look for some higher member in the series- whether this member is to become known to me through experience, or not.
Nothing further is necessary, then, for the solution of the first cosmological problem, than to decide, whether, in the regress to the unconditioned quantity of the universe (as regards space and time), this never limited ascent ought to be called a regressus in infinitum or indefinitum.
The general representation which we form in our minds of the series of all past states or conditions of the world, or of all the things which at present exist in it, is itself nothing more than a possible empirical regress, which is cogitated- although in an undetermined manner- in the mind, and which gives rise to the conception of a series of conditions for a given object.* Now I have a conception of the universe, but not an intuition- that is, not an intuition of it as a whole.Thus I cannot infer the magnitude of the regress from the quantity or magnitude of the world, and determine the former by means of the latter; on the contrary, I must first of all form a conception of the quantity or magnitude of the world from the magnitude of the empirical regress.But of this regress I know nothing more than that I ought to proceed from every given member of the series of conditions to one still higher.But the quantity of the universe is not thereby determined, and we cannot affirm that this regress proceeds in infinitum.Such an affirmation would anticipate the members of the series which have not yet been reached, and represent the number of them as beyond the grasp of any empirical synthesis; it would consequently determine the cosmical quantity prior to the regress (although only in a negative manner)- which is impossible.For the world is not given in its totality in any intuition: consequently, its quantity cannot be given prior to the regress.It follows that we are unable to make any declaration respecting the cosmical quantity in itself- not even that the regress in it is a regress in infinitum; we must only endeavour to attain to a conception of the quantity of the universe, in conformity with the rule which determines the empirical regress in it.
But this rule merely requires us never to admit an absolute limit to our series- how far soever we may have proceeded in it, but always, on the contrary, to subordinate every phenomenon to some other as its condition, and consequently to proceed to this higher phenomenon.Such a regress is, therefore, the regressus in indefinitum, which, as not determining a quantity in the object, is clearly distinguishable from the regressus in infinitum.
*The cosmical series can neither be greater nor smaller than the possible empirical regress, upon which its conception is based.And as this regress cannot be a determinate infinite regress, still less a determinate finite (absolutely limited), it is evident that we cannot regard the world as either finite or infinite, because the regress, which gives us the representation of the world, is neither finite nor infinite.
It follows from what we have said that we are not justified in declaring the world to be infinite in space, or as regards past time.For this conception of an infinite given quantity is empirical; but we cannot apply the conception of an infinite quantity to the world as an object of the senses.I cannot say, "The regress from a given perception to everything limited either in space or time, proceeds in infinitum," for this presupposes an infinite cosmical quantity; neither can I say, "It is finite," for an absolute limit is likewise impossible in experience.It follows that I am not entitled to make any assertion at all respecting the whole object of experience- the world of sense; I must limit my declarations to the rule according to which experience or empirical knowledge is to be attained.