In his comment on my earlier posting on “Science and Proof”, Kurtiss Hare raises an interesting point about the value of religion and what kind of validity criteria I was referring to, so I thought I would elaborate.

When it comes to the *value* of belief structures to an individual, then there are really no external criteria that can be imposed. For example, for someone who has experienced a personal tragedy, a belief in God and a divine purpose for life may be of far more value than all the science in the world.

The point I was trying to muddle through to about science is that it is not being “proven true” that gives scientific theories their credibility, but the fact that they seem to work well, are reliable, and can be used to make predictions.

The probability argument that Kurtiss raises is interesting but has two directions in which it can be taken. The first (which I think is the one he makes) is that the fact that very few planes crash means that the probability of that particular application of the scientific theories (i.e., arriving safely) is high.

But does that translate into a high probability of the underlying scientific theories being true? No, because if you you want to assign a “truth probability” to a scientific theory then you have to compare (for any given theory) the number of predictions that are confirmed to the total number of predictions that are conceivable. Since for any non-trivial theory the number of possible predictions is infinite, the truth probability for *any* theory (however “good”) turns out to be zero!

This seems paradoxical but philosophers of science have not been able to get around it.