Scientism refers to a belief in the universal applicability of the systematic methods and approach of science, especially the view that empirical science constitutes the most authoritative worldview or most valuable part of human learning to the exclusion of other viewpoints.MIT physicist Ian Hutchinson writes
One of the most visible conflicts in current culture is between “scientism” and religion. Because religious knowledge differs from scientific knowledge, scientism claims (or at least assumes) that it must therefore be inferior. However, there are many other important beliefs, secular as well as religious, which are justified and rational, but not scientific, and therefore marginalized by scientism. And if that is so, then scientism is a ghastly intellectual mistake. ...Sigmund responds on a leftist-atheist-evolutionist blog:
Scientism is, first of all, a philosophy of knowledge. It is an opinion about the way that knowledge can be obtained and justified. However, scientism rapidly becomes much more. It becomes an all-encompassing world-view; a perspective from which all of the questions of life are examined: a grounding presupposition or set of presuppositions which provides the framework by which the world is to be understood. In other words, it is essentially a religious position.
I’ve begun to view the use of the term “scientism” as the philosophical analogy of using the “N-word”. Scientism, the “S-word”, might be used as a positive term by a tiny minority of individuals, trying to reclaim the term from those flinging it about as a pejorative, yet the standard use remains that of a slur. The aim seems to be to portray those committed to methodological naturalism as devoid of emotion or feeling—the type of individual who would probably judge the merit of a Beethoven symphony using an oscilloscope.Wow, these folks lose their nerve easily.
This is not to say that noting the use of “scientism” is entirely without value.
Like the N-word, hearing the S-word tells us precious little about whom it is aimed but reveals a huge amount about the speaker.
Michael Shermer wrote in SciAm in 2002:
What is it about Hawking that draws us to him as a scientific saint? He is, I believe, the embodiment of a larger social phenomenon known as scientism. Scientism is a scientific worldview that encompasses natural explanations for all phenomena, eschews supernatural and paranormal speculations, and embraces empiricism and reason as the twin pillars of a philosophy of life appropriate for an Age of Science.Like any other philosophical term, it is defined a little differently by those who espouse it and those who denounce it. Scientism is defensible. It is funny how many aggressive anti-religion scientists refuse to defend it.
Update: A new book against scientism is Monopolizing Knowledge: A scientist refutes religion-denying, reason-destroying scientism, by Ian Hutchinson. Some chapter are online free.