In his essay “Three Kinds of Adaptationism” Peter Godfrey-Smith argues that the debate surrounding adaptationism actually consists of three distinct and logically independent debates. In this paper I will consider the three adaptationist positions which Godfrey-Smith sees are at stake in such debates as well as his argument for their logical independence of one another. I will then argue that Godfrey-Smith’s argument is based in premises which are not accepted by all parties in such debates and thus serves to confuse rather than clarify the issues at hand. I will then attempt to salvage a modified form of Godfrey-Smith’s argument so as to make it acceptable to all sides of the adaptationism debate and thereby achieve his goal of “classification and clarification.” (Godfrey-Smith, 1)
· Three Adaptationisms
There are, according to Godfrey-Smith, three distinct adaptationist positions which are logically independent of each other. Before considering his argument for this claim, it is important that we understand what these adaptationist positions are. Briefly, they are
- Empirical Adaptationism (EA): Adaptation due to natural selection is ubiquitous throughout the biological world.
- Methodological Adaptationism (MA): In their research, biologists ought to assume adaptation due to natural selection.
- Explanatory Adaptationism (XA): Adaptation/design due to natural selection is the answer to the most important questions in biology.
Empirical adaptationism is the position that natural selection has been the primary causal power in evolutionary history. Because natural selection has been uniquely powerful, adaptation is ubiquitous throughout the biological world. EA, then, is an adaptationist claim about the biological world, both past and present, which thus lends itself to empirical investigation. Whether the biological world has been shaped largely by natural selection to the exclusion of other evolutionary forces or not is a question which simply cannot be resolved from the armchair.
Methodological adaptationism suggests that the most efficient way to study biology is to assume some degree of adaptation or optimization. Assumptions of optimality in biology, it is argued, serve to effectively organize the biologist’s investigation and research of the biological world. MA, then, is a normative judgment about how the practice of biology ought to be carried out and normative claims do not lend themselves to empirical investigation.
Explanatory adaptationism holds that, regardless of how powerful natural selection has been in comparison to other evolutionary forces, natural selection is the unique answer to the most important questions in biology, namely those surrounding adaptation and design. XA, according to Godfrey-Smith, is a position about biologists as people rather than biology, for questions regarding adaptation and design are important from a cultural or philosophical perspective, not a biological or even a scientific one, strictly speaking. Accordingly, XA is a factual claim about biologists, not biology.
· The Logical Independence of Adaptationisms
While Godfrey-Smith certainly acknowledges that some of these adaptationist positions may find support from the other positions, he claims that all three positions are logically independent of one another. In other words, it is possible to accept or deny any combination of the three adaptationist positions without contradicting oneself. In order to demonstrate this logical independence, he provides numerous examples of how each position could be, or actually is accepted while at the same time denying the other two. Thus, each adaptationist position stands or falls independently of the other two.
Central to Godfrey-Smith’s argument are the following premises:
(1) EA is a factual claim about biology.
(2) MA is a normative judgment about the practice of biology.
(3) XA is a factual claim about biologists.
It is the logical independence of ‘is’ and ‘ought’ which allows him to separate MA from EA and XA. Additionally, it is the logical independence of factual claims regarding different domains, in this case that of biology and that of biologists, which allows Godfrey-Smith to separate EA from XA. His argument can thus be said to have the following structure:
(4) Normative judgments are logically independent of factual claims.
(5) MA is logically independent of both EA and XA. (1, 2, 3, 4)
(6) Facts about biology are logically independent of fact about biologists.
(7) EA is logically independent of XA. (1, 3, 6)
(8) EA, XA and MA are all logically independent of one another. (5, 7)
· Dennett’s Adaptationism
Godfrey-Smith’s objective in arguing for the logical independence of the three adaptationist positions is to better articulate the differences between and within adaptationist and anti-adaptationist camps. One adaptationist who he repeatedly attempts to classify according to his three positions is Daniel Dennett. What Godfrey-Smith does not seem to recognize, however, is that Dennett’s brand of adaptationism does not tolerate the distinctions which have been drawn, and this leads him to misinterpret Dennett on a number of counts. According to Dennett, all three adaptationist positions are logically entailed by the very nature of biology and as such are not logically independent of each other. By understanding Dennett’s rejection of Godfrey-Smith’s premises, and modifying the latter’s account as needed, we can thereby provide a better scheme for classification and clarification than has been provided.
Central to Dennett’s adaptationism is the difference between “the physical stance” and “the intentional stance.” The physical stance is that of viewing the world or some part of it as matter in motion; it is the stance which physical scientists necessarily adopt in their approach to the world. The intentional stance, on the other hand, is that of viewing that patterns which emerge in (what is from the physical stance) the same matter in motion with the idealizing assumption of an optimizing agent in place. For Dennett, all forms of teleology (including design, adaptation, purpose, meaning, function, etc.) exist in the natural world only when it is viewed from the intentional stance complete with its idealizing assumption of optimality. In the case of biology, the biologist views natural selection an optimizing agent constrained by time pressures and limited by a total lack of foresight. All biological systems, in turn, are the designed products of this optimizing agent.
Godfrey-Smith thus misinterprets Dennett as merely attempting to “explain the occurrence of design, purpose and meaning” within a naturalistic worldview. (Godfrey-Smith, 14) If such were the case, the former would be completely right is viewing this as a philosophical question rather than a biological one, strictly speaking. What Godfrey-Smith does not recognize is that adaptationism, according to Dennett, is logically entailed by the very existence of a biological world. In other words, without the optimizing assumption of adaptationism, there is no teleology in the world to study. Inasmuch as there is no teleology in the world to study, there is no biology to study either, for there is no biology independent of all teleology. Put yet another way, a system is only biological inasmuch as it is viewed as the product of an optimizing agent, in this case natural selection. Since viewing biology as the designed product of this optimizing agent just is adaptationism, any attempt to do away with adaptationism is logically equivalent to doing away with biology altogether. To drop all assumptions of optimality is to abandon the intentional stance, the level at which biological systems exist, in favor of the physical stance, the level at which only physical systems exist.
Accordingly, Dennett rejects premises (1), (2) and (3) in Godfrey-Smith’s argument on the grounds fail to appreciate the logical relationship which exists between biology and assumptions of optimality. The adaptationist claim, for Dennett, is not a factual or a normative one at all, but rather a logical one. This logical relationship can be seen by considering Dennett’s views regarding Godfrey-Smith’s three positions:
Adaptation due to natural selection is ubiquitous throughout the biological world (EA) because it is logically impossible for the biological world to exist independent of all adaptation.
In their research biologists ought to assume adaptation due to natural selection (MA) because it is logically impossible to do otherwise.
Adaptation/design due to natural selection is the answer to the most important questions in biology (XA) because all questions and answers in biology logically presuppose an optimizing agent and natural selection is this agent.
For Godfrey-Smith, EA, XA and MA get their logical independence in virtue of being either normative claims or factual claims about disjunctive domains. Once all three adaptationist positions are seen as logical rather than factual or normative claims their logical independence of each other breaks down. (8) must be rejected, for the teleological nature of biology logically entails EA, MA and XA. (Dennett, 260-268, 277-286)
· Revising Adaptationisms
There are two approaches which Godfrey-Smith could possibly take at this point. One approach would be to object to Dennett’s account of biology and its logical entailments. Such a move, however, would take us well beyond the scope of this paper. Furthermore, such a thing would do nothing to further Godfrey-Smith’s primary goal. His purpose is not to engage any particular position in the adaptationism debates, but rather to classify and clarify them. A better approach, then, would be to modify Godfrey-Smith’s account in a way which preserves the distinctions which he attempts to draw while at the same time incorporating Dennett’s position.
The way in which Godfrey-Smith can do this is by recognizing that the adaptationist positions which are logically entailed by Dennett’s account of biology are rather weak ones. Even if it is the case that all biological systems are the logical consequences of an optimizing process, this need not entail that each individual biological system is in fact optimized. This fact allows for modified versions of each adaptationist position which are still logically independent of one another:
o EA*: Most biological systems are more than the mere products of natural selection, they are adaptations which were selected for by natural selection.
o MA*: Biologists ought to assume that biological systems are not only the mere products of natural selection, but are adaptations which were selected for by natural selection.
o XA*: Adaptation/design due to natural selection is the answer to the most important questions in biology. (Same as XA.)
EA* moves beyond the position that all biological systems are the products of the selecting process (which is a logical truth for Dennett), and makes the stronger claim that most biological systems were actually selected for by of natural selection. This later claim surely is a factual claim about the biological world. MA* similarly moves beyond the logical truth that all biology is done with adaptationist assumptions in place, to the claim that such assumptions ought to be applied directly to all biological systems. This is clearly a normative claim which is not logically entailed by the nature of biology. EA*, according to Dennett, is a logical truth which seems to resist reformulation, though we will see that such a reformulation is unnecessary and perhaps undesirable for Godfrey-Smith’s purposes.
Given these modified descriptions of the three adaptationist positions, we can now make an argument for the logical independence of each position:
(1*) EA* is a factual claim about the biological world.
(2*) MA* is a normative judgment about the practice of biology.
(3*) XA* is a logical claim about biology in general.
(4*) Normative judgments are logically independent of factual claims.
(5*) MA* is logically independent of EA*. (1*, 2*, 4*)
(6*) Normative judgments are logically independent of logical claims.
(7*) MA* is logically independent of XA* (2*, 3*, 6*)
(8*) Factual claims are logically independent of logical claims.
(9*) EA* is logically independent of XA* (1*, 3*, 8*)
(10*) EA*, MA* and XA* are all logically independent of one another. (5*, 7*, 9*)
(1*), (2*) and (3*) preserve the basic concept in each of Godfrey-Smith’s adaptationist positions as well as their logical independence from each other while at the same time incorporating Dennett’s form of adaptationism. An interesting consequence of accepting the revised adaptationist positions is that it is no longer clear that Dennett, who is viewed by Godfrey-Smith as the strongest of adaptationists, defends EA* of MA* all that strongly. Many, but certainly not all, of Dennett’s seemingly extreme and indefensible assertions are no longer relevant (Godfrey-Smith, 6-7, 15) and he is certainly willing to temper his positions concerning EA* and MA* in the face of anti-adaptationist arguments. (Dennett, 265) Such a clear view of Dennett is exactly what Godfrey-Smith hoped to provide by isolating the three kinds of adaptationism in the first place.
· Conclusion
Godfrey-Smith’s attempt to clarify the debate surrounding adaptationism in general by demonstrating the logical independence of three distinct adaptationist positions fails. His failure to find premises that all sides of the debate(s) can agree upon only serves to further misunderstanding and confusion. We can, however, slightly modify the premises of his argument in such a way that all parties can accept them. With such modified premises in place, we can achieve the goal which Godfrey-Smith set out for himself of classification and clarification.
Bibliography:
Dennett, Daniel C.: The Intentional Stance (1987)
Godfrey-Smith, Peter: “Three Kinds of Adaptationism” in S. H. Orzack & E. Sober (eds.), Adaptationism and Optimality (2001)
