And again: man’s unity in species is not the same thing as the unity of soul and body in essence. For man’s unity in species makes clear the absolute similarity between all men, while the unity of soul and body in essence is an insult to their very existence, and reduces them to nothingness: for either the one must change into the essence of the other, or from different things something different must be produced, and so both would be changed, or if they keep to their own proper limits there must be two natures. For, as regards the nature of essence the corporeal is not the same as the incorporeal. Therefore, although holding that man has one nature, not because the essential quality of his soul and that of his body are the same, but because the individuals included under the species are exactly the same, it is not necessary for us to maintain that Christ also has one nature, for in this case there is no species embracing many subsistences.