This logical law is not violated in Jesus Christ, because he has two natures, Divine and human.
A reasonable analogy would be, say, that a virus can be alive and not-alive: not-alive because it has no cytoplasm, cell menbrane, mitochondia or organelles, it has no power of respiration, no way to absorb nutrition, and it does not grow; yet it is in another sense alive because it can use the DNA of another cell to replicate itself.
In the Incarnation of Christ, you have two different natures in one person: natures which are not confused and do not mix. So in one sense He is divine, omniscient, without beginning or end, and outside of time and space; and in another sense He is human, a learner like we are, came into being at conception, and subject to the plodding and confining limitations of time and space.
This is unprecendented; this is astonishing; but this does not violate the laws of reason.
As for "postmodernism" --- ha. Far from it. You are apparently unfamiliar with the way that wrestling with the concept of Christ's person and natures, played a seminal role in the development of Western Civilizations's concept of personhood.
Your verbal scorn makes it difficult to engage in an exchange of information. If you would be so reasonable as to look into the actual doctrine, you would not be so contemptuous.
True. I think that a lot of people make the mistake of believing that there must be a one-to-one correspondence between personhood and nature. "Nature" simply means what a thing is. So billions of different people can share the same (human) nature.
It does not necessarily follow though that one person cannot have two natures. We may not see any examples in nature, aside from Christ, but we cannot conclude that this is necessarily impossible.
God is pure spirit (purely non-material) and pure actuality. He sustains all creatures in existence. It is certainly within his power to take on the nature of an infinitely inferior creature in addition to his own nature. Whether this has happened in history would only be knowable to us through divine revelation, as is in fact the case with Christ.
See Matthew 7:6.
Francis