2p11d.md (912B)
1 The essence of man (by the Coroll. of the last Prop.) 2 is constituted by certain modes of the attributes of God, namely 3 (by II. Ax. ii.), by the modes of thinking, of all which (by II. 4 Ax. iii.) the idea is prior in nature, and, when the idea is 5 given, the other modes (namely, those of which the idea is prior 6 in nature) must be in the same individual (by the same Axiom). 7 Therefore an idea is the first element constituting the human 8 mind. But not the idea of a non–existent thing, for then (II. 9 viii. Coroll.) the idea itself cannot be said to exist; it must 10 therefore be the idea of something actually existing. But not of 11 an infinite thing. For an infinite thing (I. xxi., xxii.), must 12 always necessarily exist; this would (by II. Ax. i.) involve an 13 absurdity. Therefore the first element, which constitutes the 14 actual being of the human mind, is the idea of something actually 15 existing. Q.E.D. 16 17