If, in thus conceiving the object and the limitations of philosophy, Hume shows himself the spiritual child and continuator of the work of Locke, he appears no less plainly as the parent of Kant and as the protagonist of that more modern way of thinking, which has been called "agnosticism," from its profession of an incapacity to discover the indispensable conditions of either positive or negative knowledge, in many propositions, respecting which, not only the vulgar, but philosophers of the more sanguine sort, revel in the luxury of unqualified assurance.
The aim of the Kritik der reinen Vernunft is essentially the same as that of the Treatise of Human Nature, by which indeed Kant was led to develop that "critical philosophy" with which his name and fame are indissolubly bound up: and, if the details of Kant's criticism differ from those of Hume, they coincide with them in their main result, which is the limitation of all knowledge of reality to the world of phenomena revealed to us by experience.
The philosopher of Königsberg epitomises the philosopher of Ninewells when he thus sums up the uses of philosophy:—
"The greatest and perhaps the sole use of all philosophy of pure reason is, after all, merely negative, since it serves, not as an organon for the enlargement [of knowledge], but as a discipline for its delimitation; and instead of discovering truth, has only the modest merit of preventing error."[17]
FOOTNOTES:
[14] In a letter to Hutcheson (September 17th, 1739) Hume remarks:—"There are different ways of examining the mind as well as the body. One may consider it either as an anatomist or as a painter: either to discover its most secret springs and principles, or to describe the grace and beauty of its actions;" and he proceeds to justify his own mode of looking at the moral sentiments from the anatomist's point of view.
[15] The manner in which Hume constantly refers to the results of the observation of the contents and the processes of his own mind clearly shows that he has here inadvertently overstated the case.
[16] Locke, An Essay concerning Human Understanding, Book I, chap. i, §§ 4, 5, 6.
[17] Kritik der reinen Vernunft. Ed. Hartenstein, p. 256.