Opponents of embryonic stem cell research often highlight the similarities between babies, fetuses, and embryos, and dismiss the obvious difference between them. Their arguments almost invariably rely on the difficulty of marking precise dividing lines between them, and offer this difficulty as a reason to dismiss the distinctions outright. According to these proponents, there is only a continuum of change from embryo to baby, without any artificially differentiated stages.
Yet the fact that embryos develop into babies by degrees does not mean that there is no meaningful difference between them. When a thing evolves incrementally into something else, this gradual development does not mean they are “really” the same thing. We don’t say that cold and hot are the same merely because cold temperatures can, by degrees, increase to hot temperatures. Just as one can clearly observe that 30° F is not the same as 100° F, one can see that embryonic cells and babies are two very different entities.
Scientifically, it may be difficult to separate gradual changes into discrete stages. But no matter how difficult it is, this does not mean that such distinctions are “artificial”. Regardless of the fact that we may validly describe a certain range of temperatures as either the warm side of cold or the cold side of warm, this in no way erases the difference between hot and cold.
The difference between a bathtub full of ice and one of boiling water is only a question of degrees, yet the difference is nevertheless real. The vast gulf that separates embryo from baby is analogous. An embryo may, after a long period of gradual changes, become a baby, but that doesn’t mean it is one.
Guy received his B.A. in political science from the University of Toronto in 2004. He works for a property management/development firm in Hamilton, Ontario.