Theology Against Biology
In ancient times there were of course many misconceptions (pun intended) about conception, such as Aquinas’ belief that women were misbegotten men. But a related (another pun intended) myth still persist among some Christians, that somehow the virgin birth of Christ must have been necessary from a biological standpoint to ensure His sinlessness. A typical example is found in the articleThe Chemistry of the Blood by M. R. DeHaan:
Since there is no life in the egg until the male sperm unites with it, and the life is in the blood [Leviticus 17:11], it follows that the male sperm is the source of the blood, the seed of life. Think it through.
No, it doesn’t follow at all; this is a non sequitur. One must presume quite a lot about the statement in Leviticus, making it unsuitable as a premise in any argument. And the male sperm is no more the source of the blood than it is the source of anything else, but is merely half the genetic equation. This would in fact be the old belief that the mother contributes no genetics to the baby at all but only incubation, as recently as van Leeuwenhoek (famous for improving the microscope) in the 17th century and well into the 18th. We could just as well claim that only the woman is the source of a baby’s blood because sperm can’t create babies without eggs. Poor logic.
The biological fact is that sperm and egg each contribute half the baby’s genetics, and the blood type that the baby will have comes not from only one gamete or the other but is a matter of the possible combinations of the four blood types; see this article. But when this is not understood or accepted, it leads to faulty conclusions. The motivation for this particular one is seen in the article just before the quote about egg and sperm:
God has made of ONE BLOOD ALL THE NATIONS of the earth. Sinful heredity is transmitted through the blood and not through the flesh. Even though Jesus, therefore, received His flesh, His body from a sinful race, He could still be sinless as long as not a drop blood of this sinful race entered His veins.
Those who are familiar with my view on inheritable spiritual qualities (see Regression, Of Chickens And Eggs, Can Sin Be Inherited?, Original Sin Revisited, Blue Genes) know the problems caused by such an assertion. Here again we have two faulty premises: over-presuming the first and baselessly asserting the second. It seems that this particular view sees the problem of claiming sin is passed “through the flesh” but does not make any practical or logical improvement on it by shifting the transmission medium to blood. Flesh and blood are two different things, but both are mortal/physical/gentic entities and the phrase “one blood” is simply a figure of speech that means we are all human instead of separate created lines.
There is no logical, biological, or theological leg for any of these views to stand on. Instead, as I’ve argued many times before, Jesus’ sinlessness is by simple virtue of His conscious choice not to sin, and the significance of His virgin birth is that is was a “sign” (Matt. 1:23 referring to Isaiah 7:14) that symbolizes the difference in reaction to sin between Adam and Eve.