Why fertilizer?

Why do farmers use fertilizer? Because it enhances the yield of crops by supplementing nitrogen levels and--here I plead ignorance on the chemistry--maximizes the gains products of photosynthesis. Clearly, fertilizer is used to alter the chemical structures involved in plant life, but it does so in accordance with a certain aim. And while this aim--increased yield--is an anthropic "goal" superimposed on the crops, it is a goal fully cognizant of the crops' natural ends. Fertilizer enhances and accelerates crops' attainment of their natural ends. Farming, as Charles De Koninck points out in "The Lifeless World of Biology", is man's way of working with nature, of helping nature actualize her own potentialities. Certainly we know the chemical interactions involved in fertilization--and the application of pesticides, for that matter--are essential to the production of various ends. But the chemical interactions themselves cannot and do not bring about the natural ends involved. For, if an adequate natural explanation consisted solely in considering the physico-chemical elements and forces in any entity or system, we could bathe the crops in one chemical after another and "let the chemicals do the work." Unfortunately, while the chemicals would do what they do with relentless thoroughness, what they would do for, and to, the crops is an entirely different matter. Some of the chemicals might combine to promote crop yield, thus, of course, allowing the crops to "get what they need," but most likely we would "end up" with fields of dead crops. Why? Because what crops need is not chemical interactions as such, but fitting material "input" to produce their natural "output." Interestingly, finality is intrinsic even to physico-chemical machinations, since all such interactions are explained in roughly the same way: "Beginning with such and such elements under such and such conditions will naturally tend to result in such and such products."

Even when biotechnology "perverts" a plant's natural ends, it does so based on a concurrent grasp of how specific plants will react to various chemical changes. If the chemical alterations themselves were adequate to produce the desired changes, such changes could be applied across the board to all plants. But because we tailor our biotechnology to each specific plant, in its specific environment, we thereby recognize and "cooperate with" the plant's specific nature. Why make these changes and not others? Why avoid these changes and not others? In each case, for each aim, we alter a plant's "natural nature" (natura naturata) based on predictions which that nature will make under different conditions. A thing's act of existence--its essence--is the foundation for its reactions in existence. Indeed, prediction itself is based on the fact that plants and animals--and even molecular systems--have various analogous forms of finality. If a farmer predicted a bad harvest on the horizon, he would do so in light of his knowledge of his crops' specific natures. He would recognize where the harvest is "headed" based on how far or near from a certain end the crops are at the time he predicts a poor harvest. His resignation to this fact, and his decision, for example, not to waste fertilizer on trying to "make up for lost time," or helping the crops "catch up," is rooted in his knowledge that a chemical bath just won't be enough to attain the desired end.

I emphasize the connection between finality and prediction in light of some comments Daniel Dennett made in response to two other thinkers concerning natural teleology. He recognized that teleology--directedness or intentionality--is integral to prediction... and yet he denies what I am here calling heuristic finality actually exists in nature. Why? Because our predictions are never fully accurate. Real, heuristic teleology "is too idealized, because of the omnipresent possibility of error." Our predictions, like all ideal mathematical formulae, are idealized and therefore don't really obtain in physical reality. As an instance of an attempt to defend real teleology, Dennett cites Fred Dretske's attempt to naturalize intentionality. "Teleological principles," argues Dretske, "provide a basis for predicting what response to new circumstances a system which conforms to them will produce" (italics not in original). Dennett explains that such a system "would not just happen to track appropriateness; it would do so in a principled way. It would be caused, in Dretske's view, to track meanings in an appropriate way." This seems sensible enough, but Dennett faults it for the following reason: "But there are no such systems, human or otherwise. There are only better and worse approximations of this ideal--which is rather like the ideal of a frictionless bearing, or a perfectly failsafe alarm system." Before I comment on Dennett's "deflation" of natural teleology, I think I should explain the broader context of his views.

Dennett is well known for advocating "the intentional stance", which I have discussed before at FCA. According to the intentional stance we should act "as if" nature displays goal-directedness, since this useful fiction will help us better understand why a certain system or organism does what it does. The intentional stance is the third and highest of three stances Dennett proposes in philosophy, the second and first, respectively, being the mechanical and the physical stances. The physical stance examines the most basic physico-chemical processes of an organism/system; the mechanical examines the internal kinetics and structure that complex organism/system. In a thermostat, for example, the physical stance would help explain why the casing is "plastic," why the coiled spring-lever is "metallic," why the wires are "electroconductive," and so forth. Taking the mechanical stance would help explain why the coiled spring-lever expands or contracts and then why it closes the circuit to activate the theromstat, which, in turn, triggers the boiler to heat the air, etc. Finally, the intentional stance would have us say, tongue in cheek, that the thermostat "wants" to maintain the temperature; putting it like that is not only less cumbersome than explicating all the physical and mechanical intricacies of the contraption, but also "true in a sense" as far as our interactions with the thermostat are concerned. Similarly, a mosquito can be "refracted" by Dennett's the three stances, thus: the physical stance accounts for why its legs and wings are such a hardness, etc.; the mechanical stance accounts for why its wings elevate it at such and such a velocity and its legs help it land, etc.; finally, the intentional stance accounts for why the little demon keeps coming at us and buzzing in our ears (vit., it "wants" to feel warmth), why it extrudes a proboscis into our skin (viz., it "desires" our blood), etc. This is the context for Dennett walking a tightrope between Ringen's more austere anti-teleologism and Bennett's more Aristotelian teleology: Dennett is a teleologist in so far as taking an "intentional stance" in biology is a handy way of speaking.

Now, it should come as little surprise that I find Dennett's deflation of "real" teleology not only feeble; what may not be as obvious is that I also think it is methodologically self-destructive for him as a philosopher of science (and as a 'devout' Darwinist, to boot). In my opinion, Dennett's key argument against heuristic finality is this: "…there are no such ['really' teleological and in-principle predictable] systems, human or otherwise. There are only better and worse approximations of this ideal…" (italics not in original). As far as I understand Dennett's point, if heuristic finality is unreal due to the fact that our predictions of certain outcomes are always idealized and slightly off the mark, then our mathematical descriptions of nature are just as unreal, for they too are idealized and always slightly off the mark. This, the denial of accurate theoretical explanations of physical systems, seems like an incredibly high price to pay for deflating heuristic finality. After all, if no scientific formula is real because we never find perfectly exact manifestations of it in our quantitative observations, then can experimental science even be true in principle? If, due to physical indeterminacy and "the omnipresent risk of [observational] error," the predictive "leverage" provided by heuristic finality is unsound, then how does any other "idealized" scientific prediction hold up? If all idealized scientific theories are only useful predictive fictions, is Dennett's own pet theory of natural selection really true? If it is true merely as a "general principle," or as a researcher's working "rule of thumb" (like a biologist's reliance on the intentional stance), is natural selection accurate enough on a case by case basis to count as exact, quantitative science? If, in other words, natural selection is a logical axiom of scientific exploration, how is it any less a priori and unfalsifiable than the old Aristotelian saw that "Nature never acts without a purpose" or that "Nature abhors a vacuum"? At the same time, if natural selection is true in more than as-if, idealized way, then how does the omnipresent possibility of error and the idealized nature of theoretical prediction cut against a fruitful predictive model––including heuristic finality?

The dilemma is this: if natural selection is adequate for making clear, quantitative predictions of trait inheritance and population variation, then it is at least one instance of a predictively successful scientific theory in physical reality. If this is the case, two consequences emerge. First, the "idealization" argument against heuristic finality loses its force, since clearly at leaser certain "ideal" theories obtain in physical reality. Second, we are brought right back to the provenance of heuristic finality itself, since, if in no other case than in the theory of natural selection, there really is a place for adequate heuristic finality in science. Recall that the value of heuristic finality is that we are able to make natural predictions just because we recognize how and when specific natures act for certain ends rather than others. More generally, heuristic finality enables scientists to make accurate natural predictions based on tendencies––or, composite functions––inherent in nature at large. Interestingly, natural selection seems to provide a solid means for making just that kind of natural predictions based on a recognition that nature "tends to" work in a certain way. It is this dogged recognition of "how nature operates" as a coherently ordered system which motivates and protects experimental science. But, if Dennett is right that "there are no such [in-principle predictable] systems, human or otherwise," then natural selection itself, as a human "system" of heuristic finality, is undercut by the same token.

Unwittingly, then, Dennett seems to be advocating a fourth stance in his philosophy: the nomic stance. The nomic stance, like the intentional stance, is a useful fiction we rely on in order to render an intrinsically non-teleological world more intelligible as far as our interactions with the world are concerned. (Sound familiar?) Just as taking the intentional stance toward a thermostat is easier than doing an exhaustive physical-mechanical inventory of it, so taking the nomic stance toward nature is easier than a tedious empirical inventory of "the story so far." Under the aegis of the intentional stance, we can "play act" with nature's apparent "ends," all the while, of course, recognizing that thermometers don't really act so as to control the temperature and mosquitoes don't really act so as to suck our blood and propagate their species. Likewise, under the aegis--or should I say the spectre?--of the nomic stance, we can "play along" with nature while always reminding ourselves that there aren't really formally actual laws in nature. The nomic stance is a spectre indeed, for, if it were to take hold in the collective scientific mind––as its ancestor, Humean sensationism, never did––then science as such would self-destruct. For if there are no actual laws in nature––no real patterns which commence at X and naturally tend towards Z––then there is nothing to discover in nature. If, in turn, there is nothing to discover in nature, there is nothing for science to do. As much of a devotee of science as Dennett is, he is recklessly incautious about the fact that, if all science can "discover" is its own operational as-if "stances," then real science collapses into sheer constructivism, if not idealism.

My previous post about forms qua functional essences (and the attendant place of finality in natural selection) rather came out of the blue, but I am glad to see that it ties in, from another angle, with two largish essays that I have been working on for the past couple weeks. They deal precisely with what I think Dennett, unwittingly, both sacrifices and invokes. First, his Humean nomic stance subverts the metaphysical conviction in the existence of natural laws as a condition for science. Second, Dennett's worries about the inadequacy of theoretical idealization (or, the underdetermination of theory in general à la the Duhem-Quine thesis) invokes the metaphysical truth that, while, perfectly formal explanations do not appear "without remainder" in physical nature, yet we can and do grasp their truth precisely in a meta-physical way.

The first point is a matter of historical record. Suffice it for now to cite Stanley Jaki's immensely well informed dicta on pages 106, 107, and 109 of The Road of Science and the Ways to God:

"Clearly, Hume's posturing [in Dialogues on Natural Religion] as a champion Copernicus's and Galileo's way of thinking was an imposture. A perusal of Galileo's Dialogue should make it clear… that the creative science of Galileo was anchored in his belief in the full rationality of the universe as the product of the fully rational Creator, whose finest product was the human mind, which shared in the rationality of its Creator. … [Hume] wanted a universe of instincts, devoid of objective laws as well as of objective facts. … Typically enough, among Hume's admirers there have been many philosophers of science and even some scientists, but no great creative scientist has ever been a consistent and persistent Humean."

The second point is a strong vote of support for Thomistotelian metaphysics, anthropology, and epistemology. For if physical reality itself cannot "existentiate" formal mathematical laws, then certainly the brain as a physical organ cannot do so either, in which case the physical human brain either does not existentiate and grasp formal mathematical laws, or the human agent does so by non-physical means.

I hope to substantiate both claims in, as I say, two longish upcoming posts. Stay tuned!