2p43d.md (923B)
1 A true idea in us is an idea which is adequate in God, 2 in so far as he is displayed through the nature of the human mind 3 (II. xi. Coroll.). Let us suppose that there is in God, in so 4 far as he is displayed through the human mind, an adequate idea, 5 A. The idea of this idea must also necessarily be in God, and be 6 referred to him in the same way as the idea A (by II. xx., 7 whereof the proof is of universal application). But the idea A 8 is supposed to be referred to God, in so far as he is displayed 9 through the human mind; therefore, the idea of the idea A must 10 be referred to God in the same manner; that is (by II. xi. 11 Coroll.), the adequate idea of the idea A will be in the mind, 12 which has the adequate idea A; therefore he, who has an adequate 13 idea or knows a thing truly (II. xxxiv.), must at the same time 14 have an adequate idea or true knowledge of his knowledge; that 15 is, obviously, he must be assured. Q.E.D. 16 17