In the “Critique of the Teleological Judgment,” on account of the simplicity of the matter, we can recognise perhaps more than anywhere else Kant’s rare talent of turning a thought this way and that way, and expressing it in a multitude of different ways, until out of it there grows a book. The whole book is intended to say this alone: although organised bodies necessarily appear to us as if they were constructed in accordance with a conceived design of an end which preceded them, yet we are not justified in assuming that this is objectively the case. For our intellect, to which things are given from without and indirectly, which thus never knows their inner nature through which they arise and exist, but merely their outward side, cannot otherwise comprehend a certain quality peculiar to organised productions of nature than by analogy, for it compares it with the intentionally accomplished works of man, the nature of which is determined by a design and the conception of this design. This analogy is sufficient to enable us to comprehend the agreement of all the parts with the whole, and thus indeed to give us the clue to their investigation; but it must by no means on this account be made the actual ground of explanation of the origin and existence of such bodies. For the necessity of so conceiving them is of subjective origin. Somewhat in this way I would epitomise Kant’s doctrine on this question. In its most important aspect he had expounded it already in the “Critique of Pure Reason,” p. 692-702; V., 720-730. But in the knowledge of _this_ truth also we find David Hume to be Kant’s worthy forerunner. He also had keenly controverted that assumption in the second part of his “Dialogues concerning Natural Religion.” The difference between Hume’s criticism of that assumption and Kant’s is principally this, that Hume criticised it as an assumption based upon experience, while Kant, on the other hand, criticised it as an _a priori_ assumption. Both are right, and their expositions supplement each other. Indeed what is really essential in the Kantian doctrine on this point we find already expressed in the commentary of Simplicius on Aristotle’s Physics: “ἡ δε πλανη γεγονεν αυτοις απο του ἡγεισθαι, παντα τα ἑνεκα του γινομενα κατα προαιρεσιν γενεσθαι και λογισμον, τα δε φυσει μη ὁυτως ὁραν γινομενα.” (_Error iis ortus est ex eo, quod credebant, omnia, quæ propter finem aliquem fierent, ex proposito et ratiocinio fieri, dum videbant, naturæ opera non ita fieri._) _Schol. in Arist., ex edit. Berol._, p. 354. Kant is perfectly right in the matter; and it was necessary that after it had been shown that the conception of cause and effect is inapplicable to the whole of nature in general, in respect of its existence, it should also be shown that in respect of its qualities it is not to be thought of as the effect of a cause guided by motives (designs). If we consider the great plausibility of the physico-theological proof, which even Voltaire held to be