between beliefs which requiring proof seem to have obtained it, and beliefs which do not seem to require it.
Now the errors due to taking invalid proof for valid are the special subject of investigation in the science of Logic; and it is widely held that the labours of logicians have provided adequate criteria for excluding them: that they have discovered by analysis certain forms of reasoning into one or other of which any cogent inference may be thrown, and by the application of which the validity or invalidity of any process of inference may be made manifest. Suppose we grant this: then our epistemological problem is solved in respect of dependent or inferential beliefs—so far as the process of inference by which they are reached is capable of being thrown into a logically cogent form. That is, I can in this way obtain assurance that all my apparently proved beliefs are true if the premises from which they are inferred are true: and if these premises are themselves arrived at by inference I can similarly apply the test to the proof of them—and so on till we come to the ultimate premises. I propose to assume for the purpose of this paper that Logic has done satisfactorily what it commonly professes to have done; and that our task, accordingly, may be limited to the verification of ultimate premises, or beliefs that are in ordinary thought accepted as not requiring proof.
The importance of the task thus limited has been fully recognised by some philosophers. J. S. Mill, indeed, seems disposed to bestow on this inquiry the venerable name of “Metaphysics”. “The grand question,” he says, “of what is called Metaphysics is ‘what are the propositions that may reasonably be received without proof?’” And it is, I suppose, to propositions of this kind that Descartes’ famous criterion—expressed in the formula “that all the things which we very clearly and distinctly conceive are true”—was primarily designed to apply.
On the other hand, it seems to be also primarily to this class of propositions that Kant’s unqualified rejection of “a general criterion of truth” applies[1]—since Kant regards Logic as having adequately furnished criteria of formal truth, and therefore of all kinds of inference. In fact Kant’s condemnation of the task on which I am engaged is so strong and sweeping that I think it well to examine his arguments before proceeding further. I give it somewhat abbreviated.
“If truth consists—as is admitted—in the agreement of
- ↑ See section 3 of the Introduction to Transcendental Logic (Kritik der reinen Vernunft. Hart., p. 86).
