[...} many things must remain uncertain, and many a question insoluble, because what we know of nature is by no means sufficient, in all cases, to ex… - Immanuel Kant

Metaphysics... is nothing but the inventory of all we possess through pure reason, ordered systematically. Nothing here can escape us, because what reason brings forth entirely out of itself cannot be hidden, but is brought to light by reason itself as soon as reason's common principle has been discovered. The perfect unity of this kind of cognition, and the fact that it arises solely out of pure concepts without any influence that would extend or increase it from experience or even particular intuition, which would lead to a determinate experience, make this unconditioned completeness not only feasible but also necessary. Tecum habita, et noris quam sit tibi curta supellex. Dwell in your own house, and you will know how simple your possessions are. - Persius

We have now completely before us one part of the solution of the grand general problem of transcendental philosophy, namely, the question — How are synthetical propositions a priori possible? That is to say, we have shown that we are in possession of pure a priori intuitions, namely, space and time, in which we find, when in a judgement a priori we pass out beyond the given conception, something which is not discoverable in that conception, but is certainly found a priori in the intuition which corresponds to the conception, and can be united synthetically with it. But the judgements which these pure intuitions enable us to make, never reach farther than to objects of the senses, and are valid only for objects of possible experience.

For when we allow the arguments of reason to oppose one another with perfect freedom, something useful and serviceable for the correction of our judgements will always result, though it may not always be what we were looking for.