How Do We Know the Answer to This Question?

Carl cages, cardinal casiton, figured out the answer to all this. He says that even if man had not sinned, the son of man would have become incarnate. But it seems from scripture, from what we can tell that he did it in order to save us. That's a beautiful conundrums between competing visions of the beauty of god's work. And anagitanists on this issue, incidentally, also debated with aquinas and luther.