We must now consider what pertains to Christ's unity in common. For, in their proper place, we must consider what pertains to unity and plurality in detail: thus we concluded ([4063] Q [9]) that there is not only one knowledge in Christ, and it will be concluded hereafter ([4064] Q [35], A [2]) that there is not only one nativity in Christ.

Hence we must consider Christ's unity (1) of being; (2) of will; (3) of operation.

Under the first head there are two points of inquiry:

A1 Whether Christ is one or two?

A2 Whether there is only one being in Christ?