With this vision, Agassiz cuts through an old argument about the differential “reality” of categories in a Linnaean hierarchy: Are species real and higher levels artificial? Are all categories real or do they only express the practical needs of human convenience? If, as Agassiz argues, the entire taxonomic system, when properly “discovered,” records the structure of God's thoughts, then all categories must be objective segments of this divine totality. Only organisms have material existence, but taxonomic categories embody higher reality as direct expressions of the divine mind:
Is not this in itself evidence enough that genera, families, orders, classes, and types have the same foundation in nature as species, and that individuals [Page 273] living at the same time have alone a material existence, they being the bearers, not only of all these different categories of structure upon which the natural system of animals is founded, but also of all the relations which animals sustain to the surrounding world, — thus showing that species do not exist in nature in a different way from the higher groups, as is so generally believed? (1857, p. 7).
Agassiz shares Paley's primary goal, the fundamental “research program” of “natural theology” — to infer, from the organic works of nature, not only God's existence, but as much as possible about his intellect and goodness. Yet, despite this common aim, Paley and Agassiz could not have advocated more disparate constructions of divine presence in nature.
Every good debater, following the principle of dichotomy, knows that arguments fare best by contrast with alternatives. Moreover, the more caricatured and cardboard the alternative, the better for your side (so long as you don't depict your opponent as so much of a straw man that he becomes unbelievable). Agassiz presents his vision of classification by contrast with a “materialist” alternative of his own construction. He defines a materialist as a naturalist who attributes the forms and properties of organisms to the shaping power of constant physical laws (secondary, efficient causes), and not to direct decisions of divine will. A materialist may escape the charge of godless-ness by arguing for divine establishment of natural laws at the beginning of time. But if God then absconds forevermore, and lets nature work in such an automatic and heartless mode, what practical difference could we discern between outright materialism and such a divine clock winder? “I allude here,” Agassiz writes (p. 9) in defining his opponents, “only to the doctrines of materialists.” The issue reduces to a simple dichotomy (given the inconceivability of other alternatives, including randomness): are taxa fashioned by laws of nature (and therefore in harmony with physical order), or by God as incarnations of His categories of thought? Agassiz states the contrast, and announces his own allegiance: “Others believe that there exist laws in nature which were established by the Deity in the beginning, to the action of which the origin of organized beings may be ascribed; while according to others, they owe their existence to the immediate intervention of an Intelligent Creator. It is the object of the following paragraphs to show that there are neither agents nor laws in nature known to physicists under the influence and by the action of which these beings could have originated” (1857, p. 13).
In a grand verbal flourish, Agassiz then upholds taxonomy as the highest science, while branding the materialist alternative both dreary and soul destroying (as well as wrong). Taxonomic order records divine mentality:
I confess that this question as to the nature and foundation of our scientific classifications appears to me to have the deepest importance, an importance far greater indeed than is usually attached to it. If it can be proved that man has not invented, but only traced the systematic arrangement in nature, that these relations and proportions which exist throughout the animal and vegetable world have an intellectual, and [Page 274] ideal connection in the mind of the Creator, that this plan of creation, which so commends itself to our highest wisdom, has not grown out of the necessary action of physical laws, but was the free conception of the Almighty Intellect, matured in his thought, before it was manifested in tangible external forms, — if, in short, we can prove premeditation prior to the act of creation, we have done, once and forever, with the desolate theory which refers us to the laws of matter as accounting for all the wonders of the universe, and leaves us with no guard but the monotonous, unvarying action of physical forces, binding all things to their inevitable destiny (1857, p. 9).
By setting up his argument in this manner, Agassiz immerses himself directly into the formalist-functionalist debate — with his own version of natural theology as a strictly, almost excessively, formalist proposal: taxonomic order at all levels, not the behavior and function of individual creatures, records God's nature and intent. But by characterizing (or caricaturing) his opposition as a claim for the direct production of form by physical forces, he places the chief category of putative evidence against his vision — correlation between morphology and physical conditions of life — into the functionalist camp. (One might object in principle that such a functionalist conclusion need not follow from Agassiz's version of “materialism.” After all, morphology might be fashioned by laws of nature, but without functional excellence. Still, Agassiz's chosen definition should not be dismissed as self-serving because theorists who have espoused direct production of form by physical laws — D'Arcy Thompson (1917, 1942) in particular (see pp. 1179–1208) — have indeed used mechanical optimality as the criterion for their claim).
Thus, Agassiz commits himself to a “two-fisted” argument within the formalist-functionalist dichotomy: to demonstrate that taxonomic structure is a product of divine thought, he must show that classification records an anatomical order independent of external conditions of life (the positive argument for formalism), and also that a fit of form to immediate function cannot represent the generating principle of organic order (the negative argument against functionalism).
Agassiz, of course, does not deny that organisms tend to be well adapted; no formalist has ever made so strong a claim against the Paleyan alternative. He argues, rather — as formalists have done throughout history, no less so today than in Agassiz's time — that adaptation only expresses a secondary tinkering and minor adjustment of prior and fundamental Bauplan built by formalist principles. In its strongest version, Agassiz's brand of formalism labels adaptation as a delusion because good fit only confuses our search for a deeper order by imposing a superficial overlay of specific and immediate adaptation upon a Bauplan, thereby obscuring the more important underlying structure.
Agassiz's chief positive argument rests upon his unswerving allegiance to Cuvier's establishment of four anatomical ground plans as the foci of animal [Page 275] design: Radiata, Mollusca, Articulata, and Vertebrata.* Agassiz was particularly impressed that von Baer, the century's greatest embryologist, had, independently of Cuvier, recognized the same system by developmental standards. If morphology and embryology coincided so well, and if the greatest students of both subjects had reached agreement by such different criteria, then the fundamental principle of natural order must lie revealed:
If we remember how completely independent the investigations of K. E. von Baer were from those of Cuvier, how different the point of view was from which they treated their subject, the one considering chiefly the mode of development of animals, while the other looked mainly to their structure; if we further consider how closely the general results at which they have arrived agree throughout, it is impossible not to be deeply impressed with confidence in the opinion they both advocate, that the animal kingdom exhibits four primary divisions, the representatives of which are organized upon four different plans of structure, and grow up according to four different modes of development (1857, p. 231).
But how shall taxonomists characterize the basis for this primary division into four? As God's mind lies so far beyond our poor faculties, we cannot identify his intent (though we can certainly record his decisions); but we may surely specify the criteria that he did not use. Much of
Agassiz's Essay features a litany of claims in this negative mode: as only two alternatives exist, any argument against production of form by physical laws (a mode of origin that would induce a functional correlation of morphology and environment on the broadest scale) must provide support for the organization of relationships as categories of divine will and thought. After an introductory chapter, for example, the first two sections of Agassiz's Essay present a contrast with a common intent. How can physical laws simply produce the “best” solution for each particular circumstance if (1) identical environments house creatures of all four great body plans, and if (2) each of the body plans manages to inhabit all major environments? Agassiz summarizes: “The simultaneous existence [Page 276] of the most diversified types under identical circumstances exhibits thought, the ability to adapt a great variety of structures to the most uniform conditions. The repetition of similar types, under the most diversified circumstances, shows an immaterial connection between them; it exhibits thought, proving directly how completely the Creative Mind is independent of the influence of a material world” (p. 132).
Agassiz claimed even stronger support from the geological record. Environmental change exhibits no directional pattern through time, but life's history features progressive change (via successive creations, not by evolution) within each of the four immutable types. How could unaltered physical laws and nondirectional physical change fashion a progressive history of life?
Who could, in the presence of such facts, assume any causal connection between two series of phenomena, the one of which is ever obeying the same laws, while the other presents at every successive period new relations, an ever changing gradation of new combinations, leading to a final climax with the appearance of Man? Who does not see, on the contrary, that this identity of the products of physical agents in all ages, totally disproves any influence on their part in the production of these ever-changing beings, which constitute the organic world, and which exhibit, as a whole, such striking evidence of connected thoughts! (p. 101).
I do not claim that the refutation of Paleyan natural theology motivated this line of argument. As his major aim, Agassiz tried to debunk his caricatured version of “materialism” by showing that organisms cannot be directly constructed by physical laws. Agassiz advances his argument primarily by invoking numerous variations on the same theme: organisms do not “match” the physical world in the way that ice forms as the predictable and appropriate state for water at certain temperatures and pressures; thus, we see “how completely the Creative Mind is independent of the influence of a material world” (p. 132 as quoted above).
Agassiz begins his explicit attack on functionalism by acknowledging Paley's style of natural theology as the more common argument for God's existence and benevolence (Agassiz cites the Bridgewater Treatises, the primary Paleyan documents of his generation), but then holding that adaptation cannot represent God's primary mark upon natural history for two reasons: (1) Good correlation of function to environment would not illustrate God's care in any case, for such a relation may only record the production of form by physical causes. (2) Adaptationism fails as a generality because too many constraints, imposed by unity of type, limit any organic approach to optimality:
The argument for the existence of an Intelligent Creator is generally drawn from the adaptation of means to ends, upon which the Bridge-water Treatises, for example, have been based. But . . . beyond certain limits, it is not even true. We find organs without functions, as, for instance, the teeth of the whale, which never cut through the gum, the [Page 277] breast in all males of the class of Mammalia; these and similar organs are preserved in obedience to a certain uniformity of fundamental structure, true to the original formula of that division of animal life, even when not essential to its mode of existence. The organ remains, not for the performance of a function, but with reference to a plan (pp. 9-10).
Adaptation exists, of course, but only as a superficial and secondary overlay upon unity of type — the deeper and true reflection of God's majestic order: “When naturalists have investigated the influence of physical causes upon living beings, they constantly overlooked the fact that the features which are thus modified are only of secondary importance in the life of animals and plants, and that neither the plan of their structure, nor the various complications of that structure, are ever affected by such influences” (p. 17).
Most importantly, this deeper unity of type not only represents a natural principle in dichotomous opposition to adaptation, but also proves that creative thought, not mere mapping upon physical conditions, establishes organic order.
In all these animals and plants, there is one side of their organization which has an immediate reference to the elements in which they live, and another which has no such connection, and yet it is precisely this part of the structure of animals and plants, which has no direct bearing upon the conditions in which they are placed in nature, which constitutes their essential, their typical character. This proves beyond the possibility of an objection, that the elements in which animals and plants live . . . cannot in any way be considered as the cause of their existence (p. 33).
Having cleared away the notion that something so trivial as adaptation might represent God's signature in nature, Agassiz can now complete his ultimate defense of taxonomy as the custodian of God's presence in nature, as manifested in the broad relationships sanctioned by unity of type. Consider how much we may know of God's nature — a veritable volley of adjectives — once we locate his correct signature at the appropriate pole of nature's great dichotomy:
The products of what are commonly called physical agents are everywhere the same, (that is, upon the whole surface of the globe) and have always been the same (that is, during all geological periods); while organized beings are everywhere different and have differed in all ages. Between two such theories of phenomena there can be no causal or genetic connection. The combination of space and time of all these thoughtful conceptions exhibits not only thought, it shows also premeditation, power, wisdom, greatness, prescience, omniscience, providence. In one word, all these facts in their natural connection proclaim aloud the One God, whom man may know, adore, and love; and Natural History must, in good time, become the analysis of the thoughts of the Creator of the Universe, as manifested in the animal and vegetable kingdoms (p. 135). [Page 278]
Moreover, in understanding taxonomy as an incarnation of divine thought, we also sense our own importance in the cosmos. For if our taxonomy can mirror God's order so well, then our minds must also resemble His in principle, however infinitely poorer in capacity:
Do we not find in this adaptability of the human intellect to the fact of creation, by which we become instinctively, and, as I have said, unconsciously, the translators of the thoughts of God, the most conclusive proof of our affinity with the Divine Mind? And is not this intellectual and spiritual connection with the Almighty worthy of our deep consideration? If there is any truth in the belief that man is made in the image of God, it is surely not amiss for the philosopher to endeavor, by the study of his own mental operation, to approximate the workings of the Divine Reason, learning, from the nature of his own mind, better to understand the Infinite Intellect from which it is derived. Such a suggestion may, at first sight, appear irreverent. But, which is the truly humble? He who, penetrating into the secrets of creation, arranges them under a formula which he proudly calls his scientific system? Or he who, in the same pursuit, recognizes his glorious affinity with the Creator, and, in deepest gratitude for so sublime a birth right, strives to be the faithful interpreter of that Divine Intellect with whom he is permitted, nay, with whom he is intended, according to the laws of his being, to enter into communion? (p. 8).
With so much at stake, from the basis of natural order to confidence in our mental affinity with God himself, the primacy of broad taxonomic formalism over local adaptationism (however exquisite) becomes an issue of highest moment and pass
ion. Darwin's added dimension of history would derail Agassiz's grand design just three months after the Essay received its definitive printing, but we should remember Agassiz's effort, and grasp his argument, as perhaps the noblest brief ever presented for the centrality of systematics among the sciences.
AN EPILOG ON THE DICHOTOMY
While acknowledging some historical interest in the contrast, modern evolutionists might question, on two grounds of supposed irrelevance to current issues, the time I have taken to contrast Paley with Agassiz: (1) Paley and Agassiz struggled to find the proper signature of God in nature, and such an effort no longer counts as part of science; (2) Darwin added a third, historical dimension, thereby fracturing the old dichotomy of form and function, and rendering its terms obsolete.
I would argue, in response, that Darwin's addition, though surely the most important and revolutionary event in the history of biology scarcely rendered the old dichotomy irrelevant (see pp. 251–260 for a fuller development of this point). As Figure 4-3 shows, any morphology attributed to Darwin's historical dimension must still, by recursion, be judged by the dichotomy at its time [Page 279] of origin — that is, we must still know whether an ancestral form arose by adaptation or constraint (or by what mixture of the two poles). Thus, we may say that Darwin's new dimension expanded the scope of the dichotomy by compelling its application to two domains — past and present — when we analyze the basis of any trait in a living organism.
The Structure of Evolutionary Theory Page 45
