E1P6C
Corollary — Part I
Latin
Hinc sequitur substantiam ab alio produci non posse. Nam in rerum natura nihil datur præter substantias earumque affectiones ut patet ex axiomate 1 et definitionibus 3 et 5. Atqui a substantia produci non potest (per præcedentem propositionem). Ergo substantia absolute ab alio produci non potest. Q.E.D.
English (Elwes 1883)
Hence it follows that a substance cannot be produced by anything external to itself. For in the universe nothing is granted, save substances and their modifications (as appears from Ax. i. and Deff. iii. and v.). Now (by the last Prop.) substance cannot be produced by another substance, therefore it cannot be produced by anything external to itself. Q.E.D. This is shown still more readily by the absurdity of the contradictory. For, if substance be produced by an external cause, the knowledge of it would depend on the knowledge of its cause (Ax. iv.), and (by Def. iii.) it would itself not be substance.
Modern English
From this it follows that substance cannot be produced by anything else. For in nature there is nothing besides substances and their affections, as is clear from (E1A1), (E1D3), and (E1D5). But substance cannot be produced by another substance (E1P6). Therefore substance absolutely cannot be produced by anything else. Q.E.D.
This can also be shown more easily by reductio. For if substance could be produced by something else, its knowledge would depend on the knowledge of its cause (E1A4), and then (E1D3) it would not be substance.