The following is not a defense of naturalism, just a quick summary of the basic outlook and philosophical practice of naturalized philosophers, finishing with some standard criticisms and an indication of its current popularity. (Written for tonight's Philosophy Club discussion on naturalism at Professor Dowden's home.)
Naturalism and human knowledge
Naturalism is associated with the rejection of First Philosophy (the idea that philosophical inquiry is logically prior to scientific inquiry, and that part of the task of philosophy is to determine the scope, limits, and proper method of the latter by a priori means.) Following Hume, naturalists tend to regard FP as historically unproductive and probably incoherent. Naturalists tend to emphasize the fact that philosophers don't have special tools or methods unavailable to scientists. Hence, they tend to see philosophical knowledge and scientific knowledge as continuous rather than categorically distinct. Naturalists tend to approve of Otto Neurath's metaphor that "We are like sailors who on the open sea must reconstruct their ship but are never able to start afresh from the bottom."
Naturalism and human understanding
Naturalists tend to think that improving our understanding of the world amounts to developing theories that provide better explanations of it, which at least partly means theories that improve our ability to predict and control the future. They tend to see this process as something that is inherently unkind to existing beliefs and intuitions. As such, naturalists tend to be very dubious about philosophical inquiries that begin with questions like "What is the nature of ___?" (where the blank is filled in with words like: knowledge, time, free will, self, goodness, etc.) and which proceed by exploring our ordinary intuitions about the meaning of these words.
Naturalism and human cognition
Naturalists take it as well-established that human beings are animals and that human knowledge and understanding is an evolved capacity. They believe our claims about the world have to be compatible with a scientific understanding of our perceptual and cognitive mechanisms (which of course is still in its infancy.) This, of course, means that naturalists reject supernatural knowledge and understanding. So, for example, the idea that some of our knowledge was simply revealed to us by a supernatural agent is a non starter from a naturalistic perspective. In a similar vein, naturalists also reject the Cartesian and Platonic view that humans are born with ideas of divine origin. (They do not reject innate ideas of evolutionary origin.) Naturalists also tend to reject the idea that there are categorically distinct realms of, say, moral, aesthetic, logical and mathematical knowledge, which can be apprehended in ways that aren't answerable to a scientific understanding of our perceptual and cognitive abilities.
Naturalism and the value of philosophical inquiry
Naturalism is not associated with a distinct view of the value of philosophical inquiry. Some naturalists, such as those who participate in experimental philosophy, see themselves as scientists who study questions that have been traditionally conceived as philosophical in nature. Generally speaking they deal with naturalized versions of these questions. For example, our newest faculty member Dan Weijers, is an experimental philosopher who does empirical research on happiness. Conceived as ethics, his work might be characterized as addressing a naturalized version of a traditional ethical question: What causes happiness and how can we make more of it?
Critical stances on naturalism
Most critiques of naturalism focus on naturalism as a prescriptive account about the right way to do philosophy. The main problem with prescribing naturalism to others is that it will typically seem to involve making the kind of a priori claims that naturalists themselves reject. For example, naturalists who insist that there is, and can be, no perspective outside of science from which to evaluate scientific knowledge and understanding may appear to need to inhabit that perspective in order to substantiate the claim. Metaphysical naturalists who claim to know that there are no non-natural properties are susceptible to the same kind of criticism.
Naturalism as described here is not in any way committed to the so-called naturalistic fallacy or the is-ought fallacy.
G. Randolph Mayes
Department of Philosophy