Ramblings On Abortion, Part Two

Okay, let's talk a little more about the charged topic of abortion. Last post I created a simple syllogism to show my problem with the current state of abortion on demand:

P1: Murder is the killing of an innocent human being.
P2: A fetus is an innocent human being.
P3: Abortion is the killing of a fetus.
C: Abortion is murder.

The greatest argument I see people having is with P2, my statement that the fetus is an innocent human being. How, let's discuss that premise for a moment. There are two parts in the description of a fetus: (1) it is innocent and (2) it is a human being. Let's start with the second part first, as that seems to be the largest source of objection. Let's look at it first as a logic puzzle (ignoring for the moment any emotional appeals) and ask "What are our possible options?" These options are rather simple, either the fetus is a human being or it is not. Two options. However, the problem goes a little deeper than that as a main part of the argument of Roe (and, honestly, almost all pro-abortion arguments) deals not just with ontology but also epistemology(that is, not just what the fetus is, but what we know about what the fetus is). So, when thought of this way, the options laid out before us are as follows:

Option 1: The fetus is a human being, and we know it.
Option 2: The fetus is a human being, and we don't know it.
Option 3; The fetus is not a human being, and don't know it.
Option 4: The fetus is not a human being, and we know it.

Now, I take the position of option 1, which means that abortion does equate to murder. Most pro-abortionists would claim option 4 is correct and, if they are correct, there is no reason to disallow abortion in any case. However, a large number of people (perhaps even the majority of Americans) claim to hold one of the "agnostic" position (option 2 or option 3). In fact, Blackmum in his opinion about Roe v Wade made the statement that the Supreme Court could not settle the question of the personhood of the fetus and thus they should err on the side of pro-abortionists (essentially, we don't know what it is, so it is okay to kill it). I claim that this is the wrong path to take in the case of expressed agnosticism. In the case of option 2, abortion is at best manslaugher, the accidental killing of a human being. It's like fumigation without checking if anyone is in the building. If there is and they die, you cannot plead ignorance. Thus the more conservative approach of checking before you release the gas is the best course, that way you can say that you know the building is empty and knowingly answer the question "Is there anyone in the house?" Now what about case 3? Again with the fumigation example, you didn't check, fumigated the building, and no one died. So what? At best, you got lucky. You didn't care, you were simply irresponsible (and criminal negligence is still open as a charge). Thus to me, the agnostic position cuts the way opposite of that taken by most pro-abortionists. Being a responsible human being means erring on the side against the willful killing of the fetus.