If the divine and human natures are joined in the one person of Christ, it becomes crucial to say precisely how the natures are joined, or at least to rule out wrong answers to that question. An error called Eutychianism conceived of the two natures as merging or mingling together in the incarnation, so that divinity and humanity flowed into Christ to form an unprecedented, new, mixed nature: a divine-and-human nature. In visual terms, you could say that if divinity is yellow and humanity is blue,