same difference

Remember the little joke about ad hominems, the one your fourth grade buddy told you? "When you point a finger at me, you got three pointin' back at you."
Regarding embryonic stem cell research, and responding to a commenter, Joe Carter demonstrates the principle.

Let’s first distinguish the terms “human being” (a scientific term) and “human person” (a philosophical concept). The creation of a new human being occurs sometime in the period between the processes of gametogenesis and fertilization. Two distinct parts of other human beings (the sperm and the oocyte) combine to create a new, genetically distinct, whole living human being at the embryonic single-cell stage of development. This is, as far as I am aware, an uncontested scientific fact.... After fertilization occurs, the human embryo (regardless of the number of cells) doesn't become another kind of thing. It simply continues to grow and move through the various stages of human development until adulthood.... Sure, you can claim that it is not a "human person." But to claim that it is not a "human being" is to go against scientifically verifiable facts.

A quick scroll down the page, and we see Carter making the observation that "Also, isn't it odd that the only times people make distinctions about 'human being' and 'human person' is when they want to treat members of the human species as sub-human?"

I'm going to save a discussion of the philosophical and empirical import for another post, since I'm reading John Lizza's Persons, Humanity, and the Definition of Death, a summer reading choice sparked by this conversation in which I tried to empathize with the embryos-are-people perspective.