Moreover, if the two natures were truly one substance, and that composite were born, slapped, struck, crucified, killed, and made to suffer, it would necessarily follow that the very divinity itself was struck, crucified, killed, and subjected to pain—exactly as the Jacobites assert. This consequence applies to all Christians; it is entailed by the very creed on which their faith rests.

If, however, they reply, “Rather, the two are distinct substances, yet remain—according to us—one person without plurality,” as some among the Melkites claim, such a statement is self-contradictory; for a single person in whom there is no multiplicity is one substance, which is why it is defined as a body.

And if they liken the matter to the union of soul and body, they are forced to concede finitude. For when we speak of a human being, we describe him as one person and likewise as one substance by virtue of the union between the two. Hence he is defined as “a complete sentient body, self-moving by will, endowed with speech,” a definition that embraces both his body and his soul, and the soul and the body share a single will.

Whenever a human being decisively wills an act and possesses the power to carry it out, he performs it; there is no additional substance beside him possessing a will distinct from his own. Therefore, if they liken the union of the divinity with the humanity to this model, they must concede a single substance and a single will—precisely the position of the Jacobites.

Consequently, the soul suffers from the pains that befall the body, and it suffers