principles has sufficiently shown its invalidity. “Securus judicat orbis terrarum”; and the inadequacy of the Cartesian criterion may be thought to be now “res judicata”. On the other hand, Mr. Spencer has in recent times put forward a criterion which, so far as it relates to universal cognitions, has at least a close affinity to the Cartesian. I propose, therefore, to begin by some consideration of the earlier proposition.
I may begin by saying that Descartes’ statement of his criterion hardly satisfies his own requirements, i.e., it is not quite clear what he means by the “clearness” of a notion. I think that it will render Descartes’ meaning with sufficient precision to drop the word “clear,” keeping “distinct” (which, he says, involves “clear”), and explain a distinct notion of any object to be one that is not liable to be confounded with that of any different object—“object” being taken to denote any distinguishable element or aspect of Being, in the sense in which Descartes uses ‘Being’ as a wider term than Existence, and includes under it the objects of mathematical thought.
One further modification of Descartes’ statement seems expedient: Descartes applies the term “clear” (or “distinct”) “conception” to the cognition of the connexion of subject and predicate in a true judgment, as well as to the notions taken separately. But it seems desirable to make more explicit the distinction between the two; since the indistinctness that causes error may be held to lie not in the latter but in the former.
We may state our question, then, as follows: “Is error in universal judgments certainly excluded by a distinct conception of the subject and predicate of the judgment and of their connexion?” But this at once suggests a second question: “Why does Descartes hold it to be excluded?” And here it is noteworthy that he nowhere affirms the infallibility of his criterion to be intuitively known. He seems to have three ways of establishing it: (1) He presents it as implied in the certainty of his conscious existence (Meth., iv., and Med., iii.); (2) he presents it as a deduction from the veracity of God (Princ., xxix., xxx.); (3) he rests it on an appeal to the experience of his readers (Réponses aux IIdes Objections, Demande, vii.). The first two procedures appear to me obviously unsatisfactory[1]; I therefore propose only to consider the Empirical basis of the criterion.
- ↑ The certainty of the proposition ‘sum cogitans’ surely does not carry with it the certainty of the only discoverable general reason for accepting it as certain; and—as the veracity of God has to be demonstrated—the second procedure involves Descartes in a logical circle as has often been observed.
