The basic question is this: Seeing as Aleister Crowley was strongly opposed to abortion, which he clearly was, should Thelemites be opposed to it as well?
First off, here are my own biases on the issue. Politically, I'm strongly pro-choice. This is a largely utilitarian stance on my part because based on my study of the legal systems of various societies I have concluded that a society with options for legal abortion works better than one in which a legal prohibition scheme is in place. At the same time, I support comprehensive sex education and expanded access to contraception, both of which have been shown to bring down the abortion rate. I pretty much agree with the position advanced by the Clinton administration in the 1990's, that abortion should be safe, legal, and rare.
From the standpoint of personal ethics and values, the question of whether or not to have an abortion will always be moot for me - I'm male so I can't get pregnant. I'm not a big proponent of making judgments about other people's choices because I do tend to think that the practice of "Do what thou wilt" has a lot to do with minding my own business. I also think that using the legal system to advance my own beliefs regardless of the utilitarian consequences of the resulting laws is silly. Laws should make a society work better, and any law that doesn't should be done away with regardless of its moral foundations. So, in fact, even if I did believe abortion to be "the most shameful form of murder" (quoting Crowley) my political position would remain the same.
Nonetheless, there are serious ethical issues addressed by the abortion debate above and beyond the legal sphere and hardly anyone denies this be the case. The supposed "liberal who nonchalantly has abortions" is for the most part a strawman created by conservative commentators. I know of no one who has ever had an abortion without serious thought and consideration, liberal or conservative. Thelema as a spiritual system does provide a foundation for such thought and consideration, but as it is such a individualistic path contention between practitioners is hard to avoid. A conservative Thelemite I know once told me about an event he attended where it was automatically assumed that any Thelemite would be pro-choice when he in fact was not, and he found it ironic that this assumption would have excluded Crowley himself. Making blanket assumptions about other Thelemites is in my experience a good way to get into trouble.
Abortion is such a hot-button issue that the personal attacks pretty much fly from all directions when it comes up. For all that many of these attacks accuse the other side of "not understanding the material" there is one point that I have yet to see raised (at least outside of friends-locked LiveJournal discussions that I can't access without an account) and I think it is an important one. When Crowley talked about abortion, did he mean exactly what we mean today? According to British law, traditionally a fetus was seen as being alive following the "quickening," the moment at which independent movement of the child was first detected.
British legal scholar William Blackstone, writing in the eighteenth century, stated that:
Life ... begins in contemplation of law as soon as an infant is able to stir in the mother's womb. For if a woman is quick with child, and by a potion, or otherwise, killeth it in her womb; or if any one beat her, whereby the child dieth in her body, and she is delivered of a dead child; this, though not murder, was by the ancient law homicide or manslaughter. But at present it is not looked upon in quite so atrocious a light, though it remains a very heinous misdemeanor. (From Wikipedia)
I would be tempted to completely dismiss this concept as a legal artifact unrelated to Crowley's teachings, except that it appears he did not in fact believe that the soul entered the body at the moment of conception. Specifically, he wrote in Confessions that he believed himself to be the reincarnation of Eliphas Levi, who died on May 31st, 1875. Crowley was born on October 12th of the same year, four and a half months later, and he also wrote elsewhere that he believed that in some past life he must have taken a vow to reincarnate immediately after death. Quickening normally happens 20-some weeks into a pregnancy, so the timeline Crowley presents fits with the soul entering the body of an unborn infant at quickening rather than conception.
So does this matter to the debate at hand? Obviously I think it's relevant or I wouldn't be posting it, but I can also see the counterargument that abortion is still a violation of the formula of life and growth even if it happens before the child can be said to possess a soul, or in more scientific terms a complex nervous system that is capable of initiating movement and possibly has some degree of self-awareness. I do think it is a solid refutation of the statement that abortion of any sort denies the formula of the Minerval degree in OTO, which is specifically stated as "the soul, a wandering god, is attracted to the solar system." It would seem to me that only an abortion following the moment of quickening could really be viewed in those terms if indeed the soul isn't present for the first twenty or so weeks of pregnancy. These days, most abortions are done during the first trimester, well before quickening.
Crowley was actually kind of an odd duck as far as modern American politics goes. On the one hand, he was opposed to abortion and remained so throughout his life, and I do think anyone who contends otherwise should probably study the material in greater depth. On the other hand, it is equally clear that Crowley was strongly in favor of sexual freedom and expression. In today's politics those two beliefs rarely go together - supporters of the pro-life movement are usually opposed to homosexuality, pre-marital sex, and depictions of sexuality in just about any form. Crowley hated such beliefs, and I don't know that even his strong opposition to abortion would have allowed him much common ground with anti-sex advocates who also are pro-lifers.
Crowley's own resolution of the issue was to set up comprehensive social structures that would support women faced with unplanned pregnancies, and at one point he proposed that the OTO set up and operate an organization to do just that. Furthermore, he hoped to work at the societal level to eliminate the stigma attached to unplanned pregnancy, primarily through the promulgation of the Law of Thelema. Like many idealistic proposals, such a social system might work if the whole thing could be implemented at once, and if it could be shown to effectively reduce the demand for abortions I would be all for it. The problem is that politics doesn't usually work that way, and the OTO has never had anywhere near the funds controlled by fraternal groups like the Masons during Crowley's lifetime. Such a source of funds would be necessary for supporting such a large institution privately.
The bigger question in all of this is which of Crowley's personal beliefs are important to the practice of Thelema. I doubt anyone would contend that to be a good Thelemite you have to play chess or climb mountains. Crowley supported the British Empire - does that mean a Thelemite should be an imperialist? Crowley harshly criticized democracy as a political system - does that mean a Thelemite should be a monarchist? I certainly have met Thelemites of both descriptions, but in the end as Thelemites we are left to draw our own conclusions, "each for himself," and that really is in my opinion how it should be.
If someone is doing their practices diligently and following Crowley's spiritual system I think that is what makes them a "good Thelemite," not any particular political point of view. More to the point, I'm not even sure that we should be in the business of trying to define who is a good Thelemite and who isn't in any sort of general sense. I choose to surround myself with people who enrich my life and it just so happens that most of them are Thelemites - some with rather divergent political views on a whole variety of issues, not just this one.
I suppose now I get to find out if anyone is reading this blog. Comment away!
UPDATE: In the comments, Aish Mlchmh cited a section from Confessions in which Crowley comments on Rose trying to obtain an abortion because she believed herself to be pregnant even though she was not. He's clearly opposed to what would have been a very early term abortion, so I think any question regarding Crowley's use of the term is settled. He is using it in the contemporary sense.
I also have made a couple of changes to the original text. I removed "disreputable" from "conservative commentators" because even though when I wrote it I was trying to distinguish between reputable and disreputable conservative commentators (that is, to point out that I don't believe all conservative commentators make use of strawman arguments in the abortion debate) it reads as a cheap shot implying that all conservative commentators are disreputable. Also, I changed "the pro-life movement" to "supporters of the pro-life movement" because I was talking about particular individuals, not necessarily the organizations themselves. Finally, I changed "who is a Thelemite" in the second to last paragraph to "who is a good Thelemite" which is what I meant, but not what I first wrote.