The Hippocratic Oath has been in a parlous state, especially in the past three decades, since the rise of contemporary bioethics. Ethicists, historians, feminists, and patients' rights activists have all, for one reason or another, disparaged it. The Oath has been called outmoded, an instrument of gender discrimination, a device for professional monopoly, out of tune with societal mores, and inadequate to meet the moral demands of modern medical practice. Critics seem to agree that the Oath must be revised, replaced by a new ethic or left to physician and patient to decide for themselves.

I have dealt elsewhere with the substance of these critiques.1 Here, I wish to call to attention the curious fact that, as depreciation of the Oath has intensified, its use at commencement exercises has become virtually universal in US and Canadian medical schools.2 To be sure, with increasing usage, extensive alterations have been made to the content of the Oath. Yet, the idea of an oath persists, and indeed flourishes, almost in direct relationship to its depreciation. Clearly, medical students, faculty members and medical school deans see some lasting value in an oath at the end, and even at the beginning, of a medical education.

One may ask, What is the value of so discredited an exercise? Why does it survive? Why should it survive? Should, or, given the choice, would, medical students refuse to take it? Is the idea of an oath, Hippocratic or otherwise, merely a shard of a shattered image, or is it a seed of hope against a dispiriting future?

Its currently dubious state notwithstanding, there are several reasons why oath-taking persists and should persist:

• An oath is a solemn promise made on a solemn occasion at which medical graduates publicly declare their dedication to certain distinguishing moral commitments. This makes them de facto a moral community, a group of people united by a common ideal and together making up a single organism. Their common commitment is a reassurance to the public, a source of strength for those taking the oath and a promise that physicians will act in the interest of their patients.

• An oath sets the profession apart. It declares that those who take it are committed to something beyond self-interest. This is not commonly the case in a world where competition and self-interest are so strongly legitimised. Although this competitive element has already corroded the idea of a profession, there is enough awareness of the common bond of profession to provide a restraining force.

• An oath is also a reminder of the continuity of a profession whose roots are in antiquity. Although many medical practitioners in the past and present have violated the canons of the oath, physicians are loath to give up the ideal. They know intuitively that to do so would be to destroy the ideal and to lower the moral sights of a majority of physicians. Even those who argue strongly for the laissez faire approach to medical practice do so with the lame excuse that an oath is too "idealistic".

• An oath also has the seed of hope within it. Not that a golden age of the past will be resuscitated — there never has been a golden age of medical morality. But there have been times when physicians were more unequivocally committed than now to the good of those they serve. The pragmatists may call this impractical and unrealistic. But even pragmatists can not deny that there is something especially demanding, but, at the same time, satisfying, about caring for sick people.

What this all adds up to is the innate recognition by conscientious physicians that they are engaged in something more than commerce, industry or mere contracts for service. They may justify their lapses in behaviour by saying that change is required by the times or that it is what society wants, and so on. But no true physician can, in good conscience, destroy the archetype of medicine as a noble profession.

Yes, perhaps for many the medical oath is today a shard of a fractured ancient image. But enough of that image remains in the consciousness of the profession to remind us that to forget it entirely would be to make medicine a commercial, industrial or proletarian enterprise. We know instinctively what this would do to the care of the sick. That is why we still take oaths. Let us hope we always will.