Metaphysical Naturalism - Definition

Definition

Metaphysical naturalism is a philosophy which maintains that nature encompasses all that exists throughout space and time. Nature (the universe or cosmos) consists only of natural elements, that is, of spatiotemporal physical substance—mass–energy. For example, astronomer Carl Sagan, an agnostic, described the cosmos as "all that is or ever was or ever will be." Non-physical or quasi-physical substance, such as information, ideas, values, logic, mathematics, intellect, and other emergent phenomena, either supervene upon the physical or can be reduced to a physical account. The supernatural does not exist, which is to say, only nature is real, i.e. Atheism.

Naturalism, in recent usage, is a species of philosophical monism according to which whatever exists or happens is natural in the sense of being susceptible to explanation through methods which, although paradigmatically exemplified in the natural sciences, are continuous from domain to domain of objects and events. Hence, naturalism is polemically defined as repudiating the view that there exists or could exist any entities which lie, in principle, beyond the scope of scientific explanation.

— Arthur C. Danto, The Encyclopedia of Philosophy, Naturalism

According to Steven Schafersman, president of Texas Citizens for Science, an advocacy group opposing creationism in public schools, naturalism is a metaphysical philosophy opposed primarily by Biblical creationism."

Regarding the vagueness of the general term "naturalism", David Papineau traces the current usage to philosophers in early 20th century America such as John Dewey, Ernest Nagel, Sidney Hook and Roy Wood Sellars: "So understood, ‘naturalism’ is not a particularly informative term as applied to contemporary philosophers. The great majority of contemporary philosophers would happily accept naturalism as just characterized—that is, they would both reject ‘supernatural’ entities, and allow that science is a possible route (if not necessarily the only one) to important truths about the ‘human spirit’." Papineau remarks that philosophers widely regard naturalism as a "positive" term, and "few active philosophers nowadays are happy to announce themselves as ‘non-naturalists’", while noting that "philosophers concerned with religion tend to be less enthusiastic about ‘naturalism’" and that despite an "inevitable" divergence due to its popularity, if more narrowly construed, (to the chagrin of John McDowell, David Chalmers and Jennifer Hornsby, for example), those not so disqualified remain nonetheless content "to set the bar for ‘naturalism’ higher".

Philosopher and theologian Alvin Plantinga, a well-known critic of naturalism in general, comments: "Naturalism is presumably not a religion. In one very important respect, however, it resembles religion: it can be said to perform the cognitive function of a religion. There is that range of deep human questions to which a religion typically provides an answer ... Like a typical religion, naturalism gives a set of answers to these and similar questions."

Metaphysical naturalism is an approach to metaphysics or ontology, which deals with existence per se. It should not be confused with methodological naturalism, which sees empiricism as the basis for the scientific method. Immaterial entities can occur in a rational worldview (such as that of Plato, Aristotle, Aquinas, Newton or Darwin) which are deduced from empirical data and seen as integral to a complete understanding of natural operations.

Metaphysical naturalism regards nature as all that exists or can exist, and assumes that events in nature are explainable by empirically observable causes. However, various abstractions, such as numbers, are considered to be immaterial for practical purposes. (See Mathematical Platonism.)