Arguments from tradition

People sometimes argue from a tradition. They say things like: "Doctors should never terminate life because they never have."

Such arguments might appear to be transparently committing the naturalistic fallacy. But perhaps not: things that are traditional represent the wisdom built up over generations, and so should not be discarded lightly. People who see these arguments this way can say that their view is not that the descriptive facts about the tradition imply anything normative, but rather that these descriptive facts are evidence for some normative facts. "People wouldn't have held the view for so long unless it were true".

But arguments from tradition suffer from another problem. What the tradition is is often underdetermined by what has happened in the past.

Let's take the initial example. In the past, mental functioning and bodily functioning never came apart the way that they can with modern medicine. But that means that we have no evidence that the tradition is that doctors never take life! It might be that they never take mental life. This way of looking at things is consistent with the historical record, and also allows us to say that the tradition is one that permits euthanasia for those lacking brain function.

Another interesting example is that of marriage. Conservatives like to talk about the tradition of life-long marriage: till death do us part. But it's not inconceivable that such vows were written when death was expectable within 10 years. This means that the historical evidence is consistent with the tradition being that one should marry for no fewer than ten years. Again, that's consistent with the historical record, but implies that it's permissible to marry several times so long your life is sufficiently long.

In these cases, and others, I think we have a familiar Wittgenstinian point. If we look at how some series has played out up till now, this underdetermines description of which rule is being followed. Just as someone who counts in twos to a thousand might be following quus rather than plus, the history of marriage in humankind might be a tradition of lengthy marriages rather than of singular ones.