Let us suppose that an ichthyologist is exploring the life of the ocean. He casts a net into the water and brings up a fishy assortment. Surveying his catch, he proceeds in the usual manner of a scientist to systematize what it reveals. He arrives at two generalizations:Shermer was using this quote to say something about instrumental bias in science, but it struck me as being more relevant to the demarcation problem. The demarcation problem is the question: "What is and isn't science?" If we take the metaphorical ichthyologist's perspective, what you can't measure isn't science. What isn't science isn't real.
(1) No sea-creature is less than two inches long.
(2) All sea-creatures have gills.
In applying this analogy, the catch stands for the body of knowledge which constitutes physical science, and the net for the sensory and intellectual equipment which we use in obtaining it. The casting of the net corresponds to observations.
An onlooker may object that the first generalization is wrong. "There are plenty of sea-creatures under two inches long, only your net is not adapted to catch them." The ichthyologist dismisses this objection contemptuously. "Anything uncatchable by my net is ipso facto outside the scope of ichthyological knowledge, and is not part of the kingdom of fishes which has been defined as the theme of ichthyological knowledge. In short, what my net can't catch isn't fish.
This quote resonated with me for a moment, as I thought, "I'll have to reconsider my thoughts on science in light of this!" But when I thought it over, I realized that it only confirmed my previous ideas, which is always a disappointment.
What are these previous ideas I speak of? First, I think it's possible for there to be real things which are nonscientific. I just don't think such things are likely to have any relevance to our lives, or that it is possible to know about them. Second, I also think there are scientific things that can't be measured. That is, they're scientific in principle, but not in practice. Therefore, nowhere must I take the absurd ichthyologist's perspective.
Any reactions to the quote, perhaps opposite or completely unrelated to my own?