Barbara Forrest and Naturalism: Part 1 

I reviewed Creationism's Trojan Horse, co-authored by Barbara Forrest, about a year ago (here and here), not knowing then the prominent part she would play in the Dover ID trial. I was perplexed by the book's offhand dismissal of philosophical issues in Intelligent Design, especially given that Forrest is herself a philosopher. As it turns out, she has written about methodological and philosophical naturalism after all, in articles available here and here (see here for more from Forrest).

Her fundamental contention is that naturalism is the most rational view of the world, both methodologically (i.e., science is most fruitful when it assumes that all events have potentially discoverable natural causes) and philosophically (i.e., this is an accurate view of reality; there is no supernatural). Today I begin to review and respond to what she has written. 

I'll start by summarizing her case in the first linked article, "Methodological Naturalism and Philosophical Naturalism: Clarifying the Connection," and by offering a rejoinder to just one point in it. Further critiques will follow over the next week or so.

Forrest first defines the two versions of naturalism in terms borrowed from Paul Kurtz:

"First, naturalism is committed to a methodological principle within the context of scientific inquiry; i.e., all hypotheses and events are to be explained and tested by reference to natural causes and events. To introduce a supernatural or transcendental cause within science is to depart from naturalistic explanations. On this ground, to invoke an intelligent designer or creator is inadmissible....

"There is a second meaning of naturalism, which is as a generalized description of the universe. According to the naturalists, nature is best accounted for by reference to material principles, i.e., by mass and energy and physical-chemical properties as encountered in diverse contexts of inquiry. This is a non-reductive naturalism, for although nature is physical-chemical at root, we need to deal with natural processes on various levels of observation and complexity: electrons and molecules, cells and organisms, flowers and trees, psychological cognition and perception, social institutions, and culture..."

She adds that methodological naturalism (hereafter MN) is an epistemological principle, while philosophical naturalism (hereafter PN) is ontological or metaphysical. Her reasons for adopting PN are primarily epistemological, however. (MN is relatively uncontroversial; it's the application of its assumptions to all of reality that draws fire, and to which I will be responding here.) She says,

"[I]f there is no workable method for acquiring knowledge of the supernatural, then it is procedurally impossible to have knowledge of either a supernatural dimension or entity. In the absence of any alternative methodology, the metaphysical claims one is entitled to make are very strictly limited. The philosophical naturalist, without making any metaphysical claims over and above those warranted by science, can demand from supernaturalists the method that legitimizes their metaphysical claims. In the absence of such a method, philosophical naturalists can not only justifiably refuse assent to such claims, but can deny--tentatively, not categorically--the existence of the supernatural, and for the same reason they deny the existence of less exalted supernatural entities like fairies and ghosts: the absence of evidence."


"If supernatural causation as a methodological principle 'does not afford a basis for objective knowledge,' the implication is that methodological naturalism does afford one. If supernatural causation cannot be 'counted as a means of comprehending the universe in a scientific manner,' the implication is that methodological naturalism can be so counted upon."

She does not claim that supernaturalism is actually impossible; rather, that it has no basis in knowledge:

"This exclusivity is not mandated a priori; the philosophical naturalist justifies it on the basis of the explanatory success of science and the lack of explanatory success of supernaturalism."


"Methodological naturalism does not disallow the logical possibility that the supernatural exists. To assert categorically that there is no dimension that transcends the natural order is to assert that human cognitive capabilities are sufficient to survey the whole of what there is; such a claim would amount to epistemological arrogance. But neither does methodological naturalism allow that logical possibility is sufficient warrant for the attribution of existence. At least the naturalist position is well established with respect to the kind of cognitive capabilities we do have."


"Adopted in the sciences because of its explanatory and predictive success, methodological naturalism is the intellectual parent of modern philosophical naturalism as it now exists, meaning that philosophical naturalism as a world view is a generalization of the cumulative results of scientific inquiry. With its roots in late 19th-century science in the aftermath of Darwin's The Origin of Species, it is neither the a priori premise nor the logically necessary conclusion of methodological naturalism, but the well grounded a posteriori result."

The explanatory success of science under MN provides her with confidence in its applicability to ontology:

"Naturalist philosophers ground their philosophical naturalism in both the failure of the supernaturalist to meet Schafersman's challenge and in the success of methodological naturalism in science. This is because the reliability of knowledge depends on the method by which it is obtained, and as Schafersman says, 'science, solely because of its method, is the most successful human endeavor in history. The others don't even come close.'"


"Taken together, the (1) proven success of methodological naturalism combined with (2) the massive body of knowledge gained by it, (3) the lack of a comparable method or epistemology for knowing the supernatural, and (4) the subsequent lack of any conclusive evidence for the existence of the supernatural, yield philosophical naturalism as the most methodologically and epistemologically defensible world view."

In future posts I'll be giving more attention to this claim of science's explanatory success, which I see as greatly overstated, as well as her contention that evidence is lacking for the supernatural.

In summary, Forrest argues that PN is justified over supernaturalism because of its grounding in MN, which provides far greater epistemological support than any supernaturalist view. She allows for the logical possibility of a supernatural world but denies that we can know anything about it reliably. Therefore any speculation supernaturalism is trivial at best.

Interestingly, she quotes geologist Arthur Strahler in a passage that seems actually to rule out any possibility of the supernatural whatever. I highlight this not to suggest that is entirely her view, but to note a response she might have made to it but did not. (I must apologize for any confusion presented by my software's incapacity for block quotes. The first two paragraphs that follow are her quotation from Strahler, and the third is Forrest's response.)

[Strahler] "'A specific event of history in a specific time segment must fall into either (a) divine causation or (b) natural causation. Our logic is as follows: "If a [divine, supernatural causation], then not b [natural causation]. If b, then not a." To follow with the proposal "Both a and b" is therefore not logically possible. Moreover, one cannot get out of this bind by proposing that God is the sole causative agent of all natural causes, which in turn are the causative agents of the observed event. This "First Cause/Secondary Cause" model, long a standby of the eighteenth-century school of natural theology ... adds up to 100 percent supernatural creation.

"'Consider the analogy of cosmic history as an unbroken chain [of causal explanations] made from all possible combinations of two kinds of links, a [supernatural cause, as in religion] and b [natural cause, as in science].... When a theist declares any link in the chain to be an a-link (whereas all the others are b-links), an element of the science set has been replaced by an element of the religion set. When this substitution has been accomplished, the entire ensuing sequence is flawed by that single antecedent event of divine creation and must be viewed as false science, or pseudoscience. The reason that replacement of a single link changed the character of all ensuing links is that each successor link is dependent upon its predecessor in a cause-effect relationship ... that divine act can never be detected by the scientist because, by definition, it is a supernatural act. There exists only the claim that such an act occurred, and science cannot deal in such claims. By the same token, science must reject revelation, as a means of obtaining empirical knowledge.'

[Forrest] "Under the theistic model, according to Strahler, any recognition of natural causation is logically nullified by the simultaneous assertion of supernatural intervention, either actual or merely possible. Even while differing with Strahler on the logical impossibility of invoking both natural and supernatural explanations--it is logically conceivable if the supernatural and natural causes operate at different ontological levels--one must recognize that invoking supernatural explanations is illegitimate because of the procedural impossibility of ascertaining the facticity of the supernatural cause itself, not to mention its intervention in the chain of natural causes. This points to the metaphysical implications of methodological naturalism: if supernatural causal factors are methodologically permissible, the cosmos one is trying to explain is a non-natural cosmos."

Strahler deserves a stronger reaction than she gave here. He claims that if any link in a causal chain is "replaced by an element of the religion set," then "the entire ensuing sequence is flawed . . . and must be viewed as false science, or pseudoscience." He sets up a choice: you can have God or you can have science, but you can't have both. They are mutually exclusive. If there is the possibility of supernaturalism, there is the accompanying possibility that all science is false. This is an extremist position and should have been flagged as such; instead, Forrest gives it her qualified approval. (And the court, I'm sure, viewed her as a religion-neutral witness!)

Strahler's point, moreover, ignores much of the history of science. It has often been shown that science arose in only one culture, the Christian world of Europe, the only culture in which a rational Mind was conceived as the basis of reality. The earliest "scientists" (who more often called themselves "natural philosophers") believed they were investigating the works of God as they studied the natural world.

This did not stop science; it was precisely what was necessary for it even to get started. Note the extreme shift in mindset since then. A scientist like Strahler today will throw up his hands in the air and say, "Look, if we can't explain it all naturally, we don't have any explanations at all!" The early theistic scientists said, "If we study we can understand the world better, and thus know God more deeply." The naturalist viewpoint is independent, proud; it insists on knowing it all or not even trying. The theistic viewpoint says, "we can learn what we can learn from science and be grateful for the knowledge; and if it leads us beyond itself, so much the better."

Part 1 of a Series

Part 2
Part 3  

Posted: Sat - December 31, 2005 at 07:21 AM           |

© 2004-2007 by Tom Gilson. Permission is granted to quote up to two paragraphs of any blog entry, provided that a link back to the original is included or (in print) the website address is provided. Please email me regarding longer quotes. All other rights reserved.

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