Viewpoint subscribes to a daily quotation service from Philosophers' Magazine Online and one recent quote we received is from Karl Popper's Logic of Scientific Discovery. Popper says:
What he means by falsifiable is that any claim that aspires to the status of a scientific statement must be capable of being empirically tested. There must be some imaginable result of such testing which, if it occurred, would disprove what has been asserted. The claim might be true and such a result might never be obtained, but at least we should be able to imagine a finding which would disprove our assertion.
For example, there seem to be no conceivable facts discoverable by empiraical investigation which would falsify the claim that God exists. Therefore the claim that He does is not a scientific, but rather a metaphysical, claim.
The problem with Popper's falsifiability criterion is that it removes from the realm of science, and places squarely in the category of metaphysics, a number of assertions which scientists would like to have us believe are indeed scientific claims. An example is the claim that life began as a result of purely natural processes in the inaccessible past, or that genetic mutation and natural selection are adequate mechanisms for accounting for the great diversity of living things we find on our planet, or that consciousness arises from inert matter. None of these claims is really empirically testable. No conceivable discovery of science could show them to be false. Yet they are taught as science in our public school classrooms every day.
Meanwhile, secularists fight tooth and nail to keep Intelligent Design theory out of the classroom on the grounds that it's a metaphysical theory and as such has no place in the science curriculum. Science, we are told, limits itself only to material or natural explanations. Intelligent Design invokes a non-material source of design, an intelligence, and is therefore a philosophical, not a scientific explanation.
This is very odd since the decision to accept only naturalistic explanations is itself the result of a philosophical predilection for materialism. Scientists simply assume that materialism, a philosophical theory, is the only reliable presupposition for scientific investigation. In other words, scientists don't really banish metaphysics from the practice of science or from the classroom, they only banish metaphysics which they don't like. Sounds very scientific, don't you think?