The question of the "pernicious influence" of scientism on modern life and philosophy gets raised fairly often here at PEL. I get the sense that Wes and Seth think the influence 'quite pernicious' while Mark thinks 'not so pernicious'. (Correct me if I'm wrong guys). So I thought it would be helpful to clarify what is implied by the term, so that we might open the way for some good discussion of the issue. In my view, when we explicate the problem and put it in the right light, we should see that it is the essential problem of modern philosophy.
I recently came across the following article by Hannah Arendt, written late in her life during the 1960s. I felt that she gives here a good expression of the issue. It would not be mere political correctness to say of Hannah Arendt that she is a philosopher of the first rank, and a better critic of the modern age, our science and politics, than Heidegger was. She recognized the import of Heidegger's diagnosis of the ills of modern existence (as one of his students) while not falling prey to the naive neglect of politics in his philosophy and the terrible choices wound up making in that arena.
Her general view is shaped by the premise that, essentially, all modern philosophy and thought shows evidence of being crippled by an underlying mistake made during the development of British and European Enlightenment thinking in the 17th century. The mistake was the demotion of the classical political sense of reason and rationality, as expressed in Aristotle, for an ideal of universal rationality modeled on modern physical science, the tradition begun by Descartes.
Modeling itself on the physical scientist, modern thought tries to replace everywhere in the problems of the human condition the classical goal of philosophical and political wisdom with the goal of 'scientific' techniques, perfectly repeatable methods, and a generally utilitarian, technological attitude. Making matters even worse, the latter goal gets confused with 'reaching reality'.
In brief: modern, scientistic philosophies (Descartes, Kant, Bertrand Russell, Daniel Dennett) think that people begin alien to reality so therefore need method, procedure, and technique for reaching reality, while post-modern, anti-scientisitc philosophies (Hegel, Heidegger, Arendt, the later Wittgenstein, Richard Rorty) reject that notion as the fatal, false premise of modern thought generally, destining us for skepticism, and instead conceive of methods, techniques, and procedures as ways people change and reorganize their thinking about a reality that thought never was or is essentially apart from. Therefore the modern feels bound to the limitless problem of representation where the post-modern feels free to conceive philosophies as normative expressions of how one should think. (Recent British and American analytical philosophy remains Cartesian and Kantian in this sense, and its repeated failures to establish logically fixed epistemic foundations through a scientific method is a symptom of the disease).
On PEL, Mark is tuned in to this pivotal axis whenever he pauses to check if we are 'getting it right' or 'messing up' within a particular philosophy. Mark's phrasing here shows the normative nature of the methods held within a philosophy.
The modern switch of rank in the sense of rationality, demoting the political and promoting the technical-methodical, Arendt recognizes as the disfiguring root of most problems and failures in modern thought and many of the resulting dissatisfactions we feel in everyday modern life.
The question raised is addressed to the layman, not the scientist, and it is inspired by the humanist’s concern with man, as distinguished from the physicist’s concern with the reality of the physical world. To understand physical reality seems to demand not only the renunciation of an anthropocentric or geocentric world view, but also a radical elimination of all anthropomorphic elements and principles, as they arise either from the world given to the five human senses or from the categories inherent in the human mind.
[The scientist] has also been forced to renounce normal language, which even in its most sophisticated conceptual refinements remains inextricably bound to the world of the senses and to our common sense. For the scientist, man is no more than an observer of the universe in its manifold manifestations. The progress of modern science has demonstrated very forcefully to what an extent this observed universe, the infinitely small no less than the infinitely large, escapes not only the coarseness of human sense perception but even the enormously ingenious instruments that have been built for its refinement. The data with which modern physical research is concerned [...] are not phenomena, appearances, strictly speaking, for we meet them nowhere, neither in our everyday world nor in the laboratory; we know of their presence only because they affect our measuring instruments in certain ways. And this effect, in the telling image of Eddington, may "have as much resemblance" to what they are "as a telephone number has to a subscriber."