one with a speculative, the other with a practical content—pure mathematics and pure ethics. Has any one ever heard it alleged that, from our complete and necessary ignorance of the conditions, it is uncertain what exact relation the diameter of a circle bears to the circle in rational or irrational numbers? By the former the sum cannot be given exactly, by the latter only approximately; and therefore we decide that the impossibility of a solution of the question is evident. Lambert presented us with a demonstration of this. In the general principles of morals there can be nothing uncertain, for the propositions are either utterly without meaning, or must originate solely in our rational conceptions. On the other hand, there must be in physical science an infinite number of conjectures, which can never become certainties; because the phenomena of nature are not given as objects dependent on our conceptions. The key to the solution of such questions cannot, therefore, be found in our conceptions, or in pure thought, but must lie without us and for that reason is in many cases not to be discovered; and consequently a satisfactory explanation cannot be expected. The questions of transcendental analytic, which relate to the deduction of our pure cognition, are not to be regarded as of the same kind as those mentioned above; for we are not at present treating of the certainty of judgements in relation to the origin of our conceptions, but only of that certainty in relation to objects.
We cannot, therefore, escape the responsibility of at least a critical solution of the questions of reason, by complaints of the limited nature of our faculties, and the seemingly humble confession that it is beyond the power of our reason to decide, whether the world has existed from all eternity or had a beginning—whether it is infinitely extended, or enclosed within certain limits—whether anything in the world is simple, or whether everything must be capable of infinite divisibility—whether freedom can originate phenomena, or whether everything is absolutely dependent on the laws and order of nature—and, finally, whether there exists a being that is completely unconditioned and necessary, or whether the existence of everything is conditioned and consequently dependent on something external to itself, and therefore in its own nature contingent. For all these questions relate to an object, which can be given nowhere else than in thought. This object is the absolutely unconditioned totality of the synthesis of phenomena.