You mean this one:
I swear by Apollo the physician and Aesculapius, and Health, and All-heal, and all the gods and goddesses, that, according to my ability and judgment, I will keep this Oath and this stipulation -- to reckon him who taught me this Art equally dear to me as my parents, to share my substance with him, and relieve his necessities if required; to look upon his offspring in the same footing as my own brothers, and to teach them this art, if they shall wish to learn it, without fee or stipulation; and that by precept, lecture, and every other mode of instruction, I will impart a knowledge of the Art to my own sons, and those of my teachers, and to disciples bound by a stipulation and oath according to the law of medicine, but to none others. I will follow that system of regimen which, according to my ability and judgement, I consider for the benefit of my patients, and abstain from whatever is deleterious and mischievous. I will give no deadly medicine to any one if asked, nor suggest any such counsel; and in like manner I will not give to a woman a pessary to produce abortion. With purity and with holiness I will pass my life and practice my Art. I will not cut persons labouring under the stone, but will leave this to be done by men who are practitioners of this work. Into whatever houses I enter, I will go into them for the benefit of the sick, and will abstain from every voluntary act of mischief and corruption; and, further, from the seduction of females or males, of freemen and slaves. Whatever, in connection with my professional service, or not in connection with it, I see or hear, in the life of men, which ought not to be spoken of abroad, I will not divulge, as reckoning that all such should be kept secret. While I continue to keep this Oath unviolated, may it be granted to me to enjoy life and the practice of the art, respected by all men, in all times. But should I trespass and violate this Oath, may the reverse be my lot.
Taken absolutely literally, it only forbids one kind of abortion. I would interpret this, in light of "I will follow that system of regimen which, according to my ability and judgement, I consider for the benefit of my patients, and abstain from whatever is deleterious and mischievous" to mean avoiding any kind of abortion that is likely to be destructive to the patient, but that any kind that is likely to be helpful to be entirely legitimate. The requirement of being for the benefit of the patient is, IMHO, the ruling clause and all others are contextual interpretations of it.
Urological surgery, the Oath states, should be performed by a specialist. I don't see any technical problems with this -- I wouldn't want a GP to be performing it either. Surgery is best left to surgeons, as the Oath says. ("will leave this to be done by men who are practitioners of this work"). General Practitioners are not brain surgeons, heart surgeons, urologists, etc, and should indeed refer the patient to a specialist. (I don't consider surgeons to be doctors in the sense meant by the Oath. The Oath seems to make it clear that it is intended for village doctors making house-calls, or GPs in local practice, with similar but suitably-adjusted Oaths being required of those trained in highly specialized areas of medicine.)
Frankly, the Laws of England would be better served if attempts to revise or delete elements of Common Law were examined in light of the original intents of such law, and if both the Houses of Parliament and the practicing lawyers were familiar with the purpose of Alfred's Book of Dooms, the elimination of Sovereign Immunity in the Great Charter, and the reasoning behind the English Bill of Rights. Sure, nobody would want to revert to Saxon law, but the reasons for why it was what it was have changed surprisingly little. It was a careful balance of revenge, punishment and mercy, a balance a lot of modern laws don't have. We've progressed a lot in theory and can strike a much wiser balance today, but unless you start from the notion of a balance in the first place, you cannot hope to ever do so.
As for medical ethics having progressed, I must have missed that, what with a maker of structurally dangerous breast implants going on the lam. It was reported that the faults were spotted in 2000, but production stopped in 2011? The saline contamination at Stockport's Stepping Hill hospital is still untraced - the nurse who was suspected has since been cleared, but investigation is minimal. Dr Harold Shipman -- a name to strike fear into any reputable medical establishment. Started in med school, too. Yeah, I've some... doubts over this medical ethics bit. I may be being unfair -- certainly, much of the NHS loss of quality in the past couple of decades has been due to budget cuts, "reforms" and moving too much paperwork to medical practitioners. Long ago, the idea of the local doctor doing rounds in the neighborhood has been crushed to oblivion over the fetish for centralization. (Doctor's offices, once almost outlawed to the seriously sick to prevent disease spreading unnecessarily, have become disease central.)
I would consider the Oath to be more than a historical curiosity, just as I consider Florence Nightingale's admonishment for proper hygine and sterilization to be entirely relevant today, and consider Mrs. Mary Seacole's surgical notes to be more than a mere historical footnote. Had the Lady of the Lamp been listened to in modern days, AIDS prevention schemes (such as dispensing clean needles) would have been enacted far sooner, contamination due to unclean implements would be rarer, cross-contamination by superbugs would still be largely unheard-of, etc. I'm not saying to take these old texts literally, I'm not a fundamentalist, but rather their lessons are important and failure to listen to them in the modern world has never produced a good result.
SARS was stopped when people performed proper isolation of the disease. Sure, Florence Nightingale didn't talk about modern quarantine regulations. You have to extrapolate into the modern times, allowing and adjusting for more modern knowledge and more modern technologies. But she did talk about the dangers of allowing illnesses to spread uncontained - a lesson demonstrably not learned a hundred years later.
The Greeks were great at updating --- there's narry a single scientific, mathematical or philosophical text from ancient times that isn't riddled with corrections, updates, clarifications and replacements as understanding improved. They replaced entire lines of thinking wholesale when they were no longer useful. The same should be done today, certainly. But ethics should always start from first principles and never from modern sensibilities.
The same applies to the Oath itself. Much of it is sensibilities "modern" to that time. Extract the first principles from it, then derive the "correct" modern form of the Oath from those first principles and modern understandings. Modern political, social and religious thought should not enter into the equation. At all. Ever. The modern science and the ethical first principles should be the sole arbiters of what is ethical in medicine today. As I said in my prior post, society and the law should be subordinate to what is ultimately intended and the best way to achieve that. Society should never be in a position to mandate inferior standards and the law should never be in a position to impose impossible dilemmas. I don't care what the dollar/pound cost is, in any absolute sense. Economists should not dictate standards of living either. They may be able to say where the "sweet spot" is, where the benefits of the higher standards and superior care equal in value all of the benefits and superior standards achieved in consequence of it, but since they've done such a lousy job of even direct bean-counting I'd not hold my breath waiting. But ultimately, that should be advisory. One parameter amongst many. The ripple effect is not the only one to consider and not all ripples will be quantifiable anyway.
So, no, I don't consider it a red herring. I consider understanding the foundations on which the Oath is predicated to be sound, to understand prior architectures of ethical systems to be entirely reasonable, and to base a modern architecture on these pieces of knowledge to be entirely rational. Modern failures are almost invariably the consequences of ignoring past lessons, but you cannot learn from a history you don't know and you cannot know what it is you're to learn from history if you don't interpolate as needed but merely take texts as they stand, unchanging.