The usual line on medical ethics goes something like this. In the old days, ethics and medicine weren’t often in conflict. The physician intervened to save lives when he could, but his main limitation was technological. Nowadays, however, we have the technology to keep life going for an indeterminate period, blurring distinctions between life and death. This reality necessitates that doctors and families make difficult decisions about when to pull the plug. And since finances are always an issue, making those decisions requires us to think not just about life itself but preeminently about the quality of life.

Herein lies the supposed ethical difficulty. Issues of quality of life cannot be decided by the patient; others, especially those who pay the bill (it can be society as a whole), must intervene. As we intervene, we must remember that it’s not only the line between life and death that is no longer clear; it is equally difficult to distinguish between what might have once been called murder and what is now more correctly seen as passive euthanasia. And voilá, the unthinkable is now permissible and even ethical.

To be sure, not everyone takes it this far. But what’s missing in these discussions is an awareness that it is not the advance of medical technology by itself that creates these conflicts but the lack of a basic framework to guide us, based on time-tested rules, in making ethical decisions.

No matter the technology, doctors have always faced choices imposed by the ever-present reality of scarcity; this was as true in ancient Greece as it is today. Indeed, the ethical troubles introduced by modern medicine as such have been wildly exaggerated. We always confront the same objective: to do the best that we can to preserve life given the material world in which the means to save life are always limited while the demands are unlimited. The question of whether to do more has always been with us.

So why do we hear so much about the moral burden es with technological advance? It’s a cover for what is truly absent from modern discussions of medical ethics: a coherent framework for telling right from wrong.

There is a crucial difference between deliberate abandonment of a patient–denying food and water, for example–and failing to use every possible avenue of treatment. But what precisely is this difference? The distinction between ordinary and extraordinary means of sustenance, the most basic element of medical ethics, has been accepted from the earliest centuries of the Christian era to our own

Ordinary means include food and water, what is needed to preserve life under ordinary conditions. Extraordinary means are anything above that, which should be taken if conditions permit it but that morality doesn’t necessarily require if economics or other considerations intervene. Yet today, the field of medical ethics is dominated by endless fretting over technological woes but precious little discussion of even this basic distinction.

Technological advance, like economic progress, contains no inherent moral logic to guide it. To serve the betterment of human life, objective moral norms must serve as guideposts. This is why all social development must take place within a culture that defends human life–the only possible reason for either scientific or economic progress.

If basic moral teachings don’t always provide obvious answers in the most unusual medical cases, they at least orient us toward making ethical decisions based on a clear set of values. These choices have always confronted medical workers and always will.