If you’re a responsible scientist, you shouldn’t adopt just one worldview. In this age of tolerance and diversity, that ought to be easy to see.

Of course you do need to make a few assumptions. You need to assume that there are laws of nature—whatever they turn out to be—and that they are safe generalizations about how things go in the universe. Philosophers call that the “principle of the uniformity of nature.”

You also need to assume that we can and should acquire knowledge by something recognizable as a scientific method, which is inextricably tied to empirical investigation but takes different forms depending on the subject matter and the discipline.

But you don’t need to rule out others forms of knowledge–even knowledge of God.

To illustrate: In his classic little book On the Uses of Philosophy (1961), the philosopher Jacques Maritain, distinguishes between “exclusive” and “liberal” scientists. He defines the former thus:

“Exclusive scientists are systematically convinced that science is the only kind of genuine rational knowledge of which man is capable. For them nothing can be known to human reason except through the means and intellectual equipment of science. Exclusive scientists may be of the positivist persuasion, and consequently reject any religious belief, save perhaps some kind of mythically constructed atheistic religion… Or they may shun positivist prohibitions, and superadd to scientific knowledge a genuine, even deep religious faith, but which supposedly belongs to the world of feelings and sheer irrationality. In no case is it possible, in their eyes, to establish the existence of God with rational certainty.”

The basic assumption of exclusive scientists is what is sometimes called “scientism.” I’ve explained before why that assumption is self-refuting. Here’s how Maritain explains the same:

“To tell the truth, the assertion that there is no valid rational knowledge except perhaps that of observable and measurable phenomena is self-destructive. It itself is quite another thing than a mere expression of inter-related phenomena.” 

So that’s why we have “liberal” scientists, too:

“No wonder, consequently, that in contradistinction to exclusive scientists, ‘liberal’ scientists are to look for a rational grasping of things which passes beyond phenomena, and even… to admit the necessity of philosophy and of a properly philosophical equipment in order to make such grasping feasible, and so to complement the knowledge of nature provided by the sciences.”

Maritain pointed to Albert Einstein as a good example of a liberal scientist:

“For many years his notion of God was akin to Spinoza’s. Yet, as recent studies have shown, he came, with the progress of age and reflection, to consider the existence of that personal God whom he first doubted as required by the way nature lends itself to the rationalization of phenomena operated by science. As he said in an interview in 1950, far from being an atheist he ‘believed on the contrary in a personal God.’”

Maritain’s text contains a footnote to a German periodical in which Einstein is so quoted in 1959.

Now of course, “exclusive” scientists and their fellow-travelers would, and probably have, dismissed Einstein’s philosophical evolution as evidence of his having gone soft-headed. But that’s the sort of thing that would be said by people whose basic epistemological assumption, while hard-headed, is also self-refuting.