Mark: Abortion is wrong because fetuses are humans and it's wrong to kill humans.
Me: You're just begging the question by overloading the word "humans." When we say "fetuses are humans," we mean it in a biological sense. When we say "it's wrong to kill humans," we are no longer talking about the biological sense, but a moral one.
Today, I came across a great post at Overcoming Bias that might be helpful. Excerpt:
I think that's brilliant. Let's revisit Mark's argument, replacing "human" with membership criteria. The original argument:In the game Taboo (by Hasbro), the objective is for a player to have their partner guess a word written on a card, without using that word or five additional words listed on the card. For example, you might have to get your partner to say "baseball" without using the words "sport", "bat", "hit", "pitch", "base" or of course "baseball"...
But then, by the time I discovered the game, I'd already been practicing it for years - albeit with a different purpose.
Yesterday we saw how replacing terms with definitions could reveal the empirical unproductivity of the classical Aristotelian syllogism:
All [mortal, ~feathers, biped] are mortal;
Socrates is a [mortal, ~feathers, biped];
Therefore Socrates is mortal.But the principle applies much more broadly:
Albert: "A tree falling in a deserted forest makes a sound."
Barry: "A tree falling in a deserted forest does not make a sound."Clearly, since one says "sound" and one says "~sound", we must have a contradiction, right? But suppose that they both dereference their pointers before speaking:
Albert: "A tree falling in a deserted forest matches [membership test: this event generates acoustic vibrations]."
Barry: "A tree falling in a deserted forest does not match [membership test: this event generates auditory experiences]."Now there is no longer an apparent collision - all they had to do was prohibit themselves from using the word sound. If "acoustic vibrations" came into dispute, we would just play Taboo again and say "pressure waves in a material medium"; if necessary we would play Taboo again on the word "wave" and replace it with the wave equation. (Play Taboo on "auditory experience" and you get "That form of sensory processing, within the human brain, which takes as input a linear time series of frequency mixes.")
...
The illusion of unity across religions can be dispelled by making the term "God" taboo, and asking them to say what it is they believe in; or making the word "faith" taboo, and asking them why they believe it. Though mostly they won't be able to answer at all, because it is mostly profession in the first place, and you cannot cognitively zoom in on an audio recording.
When you find yourself in philosophical difficulties, the first line of defense is not to define your problematic terms, but to see whether you can think without using those terms at all. Or any of their short synonyms. And be careful not to let yourself invent a new word to use instead. Describe outward observables and interior mechanisms; don't use a single handle, whatever that handle may be.
Mark: Abortion is wrong because fetuses are humans and it's wrong to kill humans.
I'll let Mark respond for himself, but my guess is that he'd replace the first "humans" with something like [membership test: contains a certain subset of DNA or carries the potential of becoming the animal homo sapiens if carried to term.] When we get to the second "humans," though, it's clear there is a problem. Why should it be a priori wrong to kill [membership test: contains a certain subset of DNA or carries the potential of becoming the animal homo sapiens if carried to term?] Since when do we base morality on that sort of thing?
When I think "killing humans is wrong," I mean that "killing [membership test: is an animal that has consciousness and feelings and self-awareness] is wrong." (Obviously, there are exceptions even to that, like self-defense, but that's tangential to this post.) So the question then becomes, does a fetus pass that test? My answer is no. (It's also interesting to note that animals who are not biologically homo sapiens may pass that test, like intelligent aliens or possibly apes and dolphins. Mark would have to use a separate argument for why it's wrong to kill those creatures if in fact he thinks it is wrong.)
Now Mark has rightly pointed out that people in comas also don't have consciousness, feelings, or self-awareness, but we still think it's wrong to kill them (at least while there's hope of recovery.) That just gets into what we mean by "having" consciousness, feelings, and self-awareness. Coma patients have had it, and may have it again, so we treat them as "having" it, as far as the question of killing goes. Fetuses have never had it, although they may have it in the future.
It's perfectly rational then, to argue that "killing [membership test: is an animal that has consciousness and feelings and self-awareness or will have them]" is wrong as well, but then one would have to justify that claim, rather than relying on the humans-humans argument. I'm not trying to prove that abortion is okay in this post, just that the humans-humans argument is sophistry.
