c. What comes third is thus the transition of this certainty into truth, into the determinate; Descartes again makes this transition in a naïve way, and with it we for the first time begin to consider his metaphysics. What here takes place is that an interest arises in further representations and conceptions of the abstract unity of Being and Thought; there Descartes sets to work in an externally reflective manner. “The consciousness which merely knows itself to be certain now however seeks to extend its knowledge, and finds that it has conceptions of many things—in which conceptions it does not deceive itself, so long as it does not assert or deny that something similar outside corresponds to them.” Deception in the conceptions has meaning only in relation to external existence. “Consciousness also discovers universal conceptions, and obtains from them proofs which are evident, _e.g._ the geometric proposition that the three angles of a triangle are together equal to two right angles is a conception which follows incontrovertibly from others. But in reflecting whether such things really exist doubts arise.”[168] That there is such a thing as a triangle is indeed in this case by no means certain, since extension is not contained in the immediate certainty of myself. The soul may exist without the bodily element, and this last without it, they are in reality different; one is conceivable without the other. The soul thus does not think and know the other as clearly as the certainty of itself.[169]