plicable -- just some more of the basic postulated correlations in science. But I can think of only one or two such, compared with the embarras des richesses psychophysical dualism yields. This is contrary to the spirit of scientific economy and yet apparently inescapable. There is just one ray of hope here. The correlations are not between two independently identifiable properties, a fact recognized in the old "Perhaps when you see green, you see what I see when I see red" puzzle. I believe this ray of hope actually sheds enough light to get us out of the dualistic darkness and into the (dualistic) light. Similarly, I think we can demonstrate the truth of interactionism as an answer to the first question -- which kind of dualism should we adopt. But I only think this: I have not yet found or constructed such a proof.
To conclude then, let me remind you of a development in the history of biology of great importance to us. For a long time there was a popular school of theoretical biology -- it still has its supporters -- the entelechists, which maintained that purposive behavior in organisms clearly demonstrated the falsehood of mechanism. This was simply a logical error, but it had serious scientific and social consequences for the entelechists. Scientifically, it misled them into fruitless theorizing about élan vital etc.; sociologically, it made them the reactionaries of the continuing scientific revolution in biology -- they became the old men, the foes of progress. We cannot afford those consequences. At the very least we should recognize the primacy of the facts about ESP phenomena over any metaphysical framework commitments we may have, and their compatibility with several alternative frameworks. It is particularly tempting for the worker in an unpopular field to see the prevalent ideology of the conventional scientist as culpable for the unpopularity and the criticisms; and he may be supported in this view by the conventional scientist. Both are usually, and in the present case definitely, incorrect.
Thus I believe we face a double danger; over the evidence and over the interpretation of the evidence. If we do not exhibit a willingness to redo old work and rethink old thoughts I am afraid we shall find that the processes of evaporation and absorption will remove our subject matter.