Saturday, 4 June 2011

Vincible ignorance

Last week, a friend pointed out an inadequacy in my terminology. I referred to people who do not believe in evolution. She pointed out that we should refer to people who do not know about evolution. The creationists and the advocates of intelligent design are just plain ignorant.

If we take a couple of reasonably uncontroversial principles, that knowledge implies true belief and that doxastic voluntarism is suspect, we can unpack this a little.

Given that the broad evolutionary account is true, and that there is a stack of evidence for it, and that research institutions and practices are such that we probably would not believe it if it were false (satisfying a tracking condition), those who do believe it and who are sufficiently in touch with the progress of science that they would become aware of major changes in the direction of thought, also know it. And those who do not believe it certainly do not know it, because knowledge requires belief.

Then we come on to the accusation of ignorance. This is not, in this context, a mere accusation of failure to be aware. The creationists and the advocates of intelligent design do know about evolution, to a limited extent. They are aware of the evolutionary account in outline, and of some of the evidence. But they claim to have weighed the evidence and to have rejected evolution.

It is easy to suspect them of straightforward doxastic voluntarism. It looks very much as though they have decided to reject evolution, and have then deliberately misread some evidence, and ignored other evidence, in order to support that position. The obvious motive would be to bolster their position within a group of people, usually a religious or religious-political group, who take pride in something that from the outside can be seen to be intellectual perversity. The perversity is a great instrument for distinguishing between the in-group and the out-group. If you can only join by professing to believe something that goes against the grain of rational thought, that gives the group a certain exclusivity.

There is, however, another twist. It seems unlikely that many people could live with naked doxastic voluntarism. That is why flat-Earth societies and the like have very few members. It would be almost as hard to live with a nakedly selective choice of evidence, to know that one had looked at certain fossils but had deliberately ignored others.

I suspect that what allows those who reject evolution to live with themselves is the fact that the evidence is far more subtle and extensive than a collection of fossils in a glass case. We have genetic mechanisms, features of the genome that can be traced across species, the geographical distribution of species, and so on. One needs some understanding of genetics, of molecular biology, and of mathematics, to grasp the significance of all that evidence. So those who lack such understanding can overlook the evidence without deliberately rejecting it.

That is where we should level the charge of ignorance at creationists and at the advocates of intelligent design. They simply do not know enough to grasp the evidence. My friend was correct to say that they do not know about evolution, but primarily because knowing about it means more than knowing the rough outline. That is also why it is so hard to convert them to good sense. They need to go back to school first.

Sometimes, one observes the same phenomenon in other fields. I once knew someone who was utterly convinced that something supernatural was going on when people walked across glowing coals. It had to be, because the coals were at a thousand or so degrees. I tried to explain that while the temperature was high, the thermal energy that was held by the coals was low, so the temperature of the coal-walker's feet did not rise to a thousand degrees. (Do not try this at home: it can go wrong, and people do get badly burnt.) Alas, she just did not have the concept of thermal capacity, and probably did not have the concept of energy as it is defined within physics.


  1. If you say that someone does not know about the evolution you imply that they have never heard about it.
    So "not knowing" is not a good alternative to "not believing".

    If they have heard about it but do not think it is true then perhaps they have not understood it properly.

    What would be the most perfect expression for your friend´s idea ?

  2. We must distinguish between two senses of "not knowing about". There is the sense of "have never heard of". That is the wrong sense here, because people who advocate creationism or intelligent design have heard about evolution, and they know the general idea. Then there is the sense of "not knowing enough about to make a proper judgement". That is the sense we need here. In that sense, people who advocate creationism or intelligent design do not know about evolution. So yes, they have not understood properly. In particular, they have not understood the evidence. I hope that makes it clearer.

  3. Why is it called a THEORY of evolution then ?
    A theory is just a model of explanation which is open to revision when new evidence shows up that is incompatible with the model.
    If evolution is as clear as a geometrical proof it should be called something like "law of evolution".

  4. I think there are two answers, depending on whether we consider the broad outline or the technical details.

    If we consider the broad outline, the idea that species evolved from one another over long periods through natural processes such as random genetic mutation and pressures of selection, we cannot see how this picture will ever be overthrown. It might be, but that is so unlikely that it is not worth taking seriously. So call it a theory if you like, but it would be very odd not to accept it as plain fact.

    If we consider the technical details, not everything is settled yet. So if someone takes a view on some detail, based on limited evidence, we can easily see how new evidence might require a change of view. Then it would make sense to say "there is a theory which says such and such about this detail, but it is unproven".

    Of course, there is another sense of "theory", in which the word means a systematic and integrated explanation which makes sense of a good deal of evidence. Something can be a theory in that sense even if no-one can seriously doubt it.

  5. Is it so obvious that species evolved from one another ?
    Would a frog with half a wing be more able to survive than a frog with no wings ?
    The half-species, on the way to full species, do not make much sense.

  6. Of course there are questions about exactly what happened at each stage, and we do not have all the answers yet. But we have such massive evidence for evolution that such gaps in our knowledge should not undermine our belief in evolution in general. The only sensible attitude is that we have to do more work to explain all the details. It would be utterly at variance with reason to allow little problems like that to sidetrack us into taking any interest in creationism or intelligent design. Just think how much either idea, creationism or intelligent design, would be disconnected from our entire understanding of the Universe.