truth," and through which, therefore, knowledge in its perfection, is possible, and is alone possible. The criterion of truth is to be regarded as the positive or final element in the Cartesian Method; for, besides now superseding doubt as the regulative principle of the Cartesian Analysis, it is likewise constituted the regulative principle of the Cartesian Synthesis.
There thus falls to be considered, in the fifth place, the Cartesian Criterion of truth.
V. According to Descartes, certainty, or assurance is not identical with the criterion of truth. The latter, or that through which we know that we possess truth, is the ground or source of certainty, or assurance: but as we must possess certainty before we can seek its ground or source, it is plain that, in the order of knowledge, assurance or the supposition that we possess truth is prior to our discovery of the ground of certainty, or the criterion of truth.
Hence it is that Descartes does not seek to discover, in the first instance, the criterion of truth, but only some judgment absolutely certain and indubitable: in other words, he allows the faculties of knowledge to spring into activity and form a product, that is, to affirm their own credibility, before he essays to determine that condition of cognitive activity, the consciousness of which is certainty. Descartes thus essays to determine not what must be the criterion of truth, but to discover what is, or by analysis to find that element in a knowledge, on the consciousness
