We consider how to discern whether or not evolution is taking place in an observed system. Evolution will be characterized in terms of a particular macroscopic behavior that emerges from microscopic organismic interaction. We de ne evolutionary activity as the rate at which useful genetic innovations are absorbed into the population. After measuring evolutionary activity in a simple model biosphere, we discuss applications to other systems. We argue that evolutionary activity provides an objective, quantitative interpretation of the intuitive idea of (...) biological teleology. We also propose using evolutionary activity in a test for life. (shrink)

The prevalence of optimality models in the literature of evolutionary biology is testimony to their popularity and importance. Evolutionary biologist R. C. Lewontin, whose criticisms of optimality models are considered here, reflects that "optimality arguments have become extremely popular in the last fifteen years, and at present represent the dominant mode of thought." Although optimality models have received little attention in the philosophical literature, these models are very interesting from a philosophical point of view. As will be argued, optimality models (...) are central to evolutionary thought, yet they are not readily accomodated by the traditional view of scientific theories. According to the traditional view, we would expect optimality models to employ general, empirical laws of nature, but they do not. Fortunately, the semantic view of scientific theories, a recent alternative to the traditional view, more readily accomodates optimality models. As we would expect on the semantic view, optimality models can be construed as specifications of ideal systems. These specifications may be used to describe empirical systems--that is, the specifications may have empirical instances. But the specifications are not empirical claims, much less general, empirical laws. Although philosophers have yet to discuss the general features and uses of optimality models, these topics have stimulated much recent discussion among evolutionary biologists. Their discussions raise a number of precautions concerning the proper use of optimality models. Moreover, many of their caveats can be interpreted as general reminders that 1) optimality models specify ideal systems whose empirical instantiations may be quite restricted, and that 2) optimality models should not be construed as general, empirical laws. As G. F. Oster and E. O. Wilson caution, "the prudent course is to regard optimality models as provisional guides to further empirical research and not necessarily as the key to deeper laws of nature." It seems, then, that the semantic view of theories is more sensitive to the nature and limitations of optimality models than is the more traditional view of theories. (shrink)

The ultimate source of explanation in biology is the principle of natural selection. Natural selection means differential reproduction of genes and gene combinations. It is a mechanistic process which accounts for the existence in living organisms of end-directed structures and processes. It is argued that teleological explanations in biology are not only acceptable but indeed indispensable. There are at least three categories of biological phenomena where teleological explanations are appropriate.

There are no "special sciences" in Fodor's sense. There is a large group of sciences, "historical sciences," that differ fundamentally from the physical sciences because they quantify over a different kind of natural or real kind, nor are the generalizations supported by these kinds exceptionless. Heterogeneity, however, is not characteristic of these kinds. That there could be an univocal empirical science that ranged over multiple realizations of a functional property is quite problematic. If psychological predicates name multiply realized functionalist properties, (...) then there is no single science dealing with these: human psychology, ape psychology, Martian psychology and robot psychology are necessarily different sciences. (shrink)

Perceptions "present" objects as red, as round, etc.-- in general as possessing some property. This is the "perceptual content" of the title, And the article attempts to answer the following question: what is a materialistically adequate basis for assigning content to what are, after all, neurophysiological states of biological organisms? The thesis is that a state is a perception that presents its object as "F" if the "biological function" of the state is to detect the presence of objects that are (...) "F". The theory contrasts with causal/informational theories, and with internalist theories, for example those which assign content on the basis of introspected feel. Its advantages are that it permits perceptual error while at the same time allowing content to be expressed in terms of external properties. The argument of the paper is illustrated throughout by examples from biology and computational psychology. (shrink)

I defend the historical definition of "function" originally given in my Language, Thought and Other Biological Categories (1984a). The definition was not offered in the spirit of conceptual analysis but is more akin to a theoretical definition of "function". A major theme is that nonhistorical analyses of "function" fail to deal adequately with items that are not capable of performing their functions.

But what are functions? Here, 15 leading scholars of philosophy of psychology and philosophy of biology present new essays on functions.

I try to focus our differences by examining the relation between what Dennett has termed "the intentional stance" and "the design stance." Dennett takes the intentional stance to be more basic than the design stance. Ultimately it is through the eyes of the intentional stance that both human and natural design are interpreted, hence there is always a degree of interpretive freedom in reading the mind, the purposes, both of Nature and of her children. The reason, or at least a (...) reason, is that intentional interpretation is holistic, hence indeterminate, for the kinds of reasons given by Davidson and Quine. In contrast, I take the design stance to be more basic than the intentional stance. Intentional attributions express our best guesses about the locations of effects of certain kinds of natural design. And although there is often indeterminacy, ambiguity, or vagueness concerning what it is that natural selection (or learning) has selected for, these indeterminacies and vaguenesses are local, not holistic. There is reason to suppose that the better portion of Nature's purposes and the intentional states of her children are determinate in content within quite closely defined limits. I propose to defend this position as well as I can, so as to call from Dennett his own views on precisely where our paths separate (if they really do). (shrink)

I examine the way in which Daniel Dennett (1987, 1995) uses his 'intentional' and 'design' stances to make the claim that intentionality is derived from design. I suggest that Dennett is best understood as attempting to supply an objective, nonintentional, naturalistic rationale for our use of intentional concepts. However, I demonstrate that his overall picture presupposes prior application of the intentional stance in a preconditional, ineliminable,'sense-giving' role. Construed as such, Dennett's account is almost identical to the account of biological teleology (...) offered by Kant in The Critique of Judgement, with the consequence that Dennett's naturalism is untenable. My conclusions lead to doubts concerning the legitimacy of any account attempting to naturalise intentionality by extracting normativity from biology and also point to a novel account of biological function. (shrink)

The title of The Rediscovery of the Mind suggests the question "When was the mind lost?" Since most people may not be aware that it ever was lost, we must also then ask "Who lost it?" It was lost, of course, only by philosophers, by certain philosophers. This passed unnoticed by society at large. The "rediscovery" is also likely to pass unnoticed. But has the mind been rediscovered by the same philosophers who "lost" it? Probably not. John Searle is an (...) analytic philosopher, with some of the same notions as the positivists and behaviorists who rejected consciousness and "lost" the mind in the first place, but he also does not sound like the kind of reductionist who would have joined that crowd. His views, indeed, are sensible enough, and some of his insights so important, that it is a shame to find his thought profoundly limited by some of the same mistakes and prejudices that ruined philosophy, and not just philosophy of mind, under the influence of those positivists and behaviorists. There is enough of genuine value in his treatment, that it can easily be taken up and, with relatively slight modification, added to what is of permanent value in the history of philosophy. (shrink)

This 2001 book offers an examination of functional explanation as it is used in biology and the social sciences, and focuses on the kinds of philosophical presuppositions that such explanations carry with them. It tackles such questions as: why are some things explained functionally while others are not? What do the functional explanations tell us about how these objects are conceptualized? What do we commit ourselves to when we give and take functional explanations in the life sciences and the social (...) sciences? McLaughlin gives a critical review of the debate on functional explanation in the philosophy of science. He discusses the history of the philosophical question of teleology, and provides a comprehensive review of the post-war literature on functional explanation. What Functions Explain provides a sophisticated and detailed Aristotelian analysis of our concept of natural functions, and offers a positive contribution to the ongoing debate on the topic. (shrink)

Combining ideas from philosophy, artificial intelligence, and neurobiology, Daniel Dennett leads the reader on a fascinating journey of inquiry, exploring such intriguing possibilities as: Can any of us really know what is going on in someone else's mind? What distinguishes the human mind from the minds of animals, especially those capable of complex behavior? If such animals, for instance, were magically given the power of language, would their communities evolve an intelligence as subtly discriminating as ours? Will robots, once they (...) have been endowed with sensory systems like those that provide us with experience, ever exhibit the particular traits long thought to distinguish the human mind, including the ability to think about thinking? Dennett addresses these questions from an evolutionary perspective. Beginning with the macromolecules of DNA and RNA, the author shows how, step-by-step, animal life moved from the simple ability to respond to frequently recurring environmental conditions to much more powerful ways of beating the odds, ways of using patterns of past experience to predict the future in never-before-encountered situations. Whether talking about robots whose video-camera ”eyes” give us the powerful illusion that ”there is somebody in there” or asking us to consider whether spiders are just tiny robots mindlessly spinning their webs of elegant design, Dennett is a master at finding and posing questions sure to stimulate and even disturb. (shrink)

Transcending the various formal concepts of life, this captivating book offers a unique overview of life's history, essences, and future. "A masterpiece of scientific writing. You will cherish "What Is Life?" because it is so rich in poetry and science in the service of profound philosophical questions".--Mitchell Thomashow, "Orion". 9 photos. 11 line illustrations.

In this paper, we advocate the idea that an adequate explanation of biological systems requires appealing to organizational closure as an emergent causal regime. We first develop a theoretical justification of emergence in terms of relatedness, by arguing that configurations, because of the relatedness among their constituents, possess ontologically irreducible properties, providing them with distinctive causal powers. We then focus on those emergent causal powers exerted as constraints, and we claim that biological systems crucially differ from other natural systems in (...) that they realize a closure of constraints, i.e. a second-order emergent regime of causation such that the constituents, each of them acting as a constraint, realize a mutual dependence among them, and are collectively able to self-maintain. Lastly, we claim that closure can be justifiably taken as an emergent regime of causation, without admitting that it inherently involves whole-parts causation, which would require to commit to stronger ontological and epistemological assumptions. (shrink)

We can readily identify goal-directed systems and distinguish them from non-goal-directed systems. A woodpecker hunting for grubs is the first, a pendulum returning to rest is the second. But what is it to be a goal-directed system? Perhaps the dominant answer to this question, inspired by systems theories such as cybernetics, is that goal-directed systems are distinguished by their tendency to seek, aim at, or maintain some more-or-less easily identifiable goal. Cybernetics and the like would hold that physical systems subject (...) only to physical laws can exhibit such behavior. If sound, this systems approach to teleology would unify a diverse range of goal-directed phenomena and neatly side-step many traditional bogey-men of teleology, such as anthropomorphism and future causation. Goal-directed phenomena would be a normal feature of the natural causal world that could be described in purely descriptive and quantitative terms, and receive ordinary causal explanations. Thus, the systems approach promises to provide a naturalistic-cum-descriptive account of teleology suitable for use in naturalistic accounts of other phenomena, including the intentionality of mental states and even self-consciousness. (shrink)

In this paper, I try to develop an account of functions which might be of use to a biologist engaged in classifying and explaining natural phenomena. The most pressing difficulty facing such an account is the need to reconcile the normativity of function statements with their explanatory force. I consider two familiar accounts of function statements, offered by Andrew Woodfield and Larry Wright . I examine both accounts in search of the strongest possible formulation of each type of theory. I (...) fail to find a formulation of the ACT which is completely immune from counterexamples, but I do find a satisfactory formulation of the HT. In particular, I argue that the HT should incorporate a point central to the ACT that functions involve a means/end relationship between two devices. I then consider functional explanations: I argue that an ACT which holds that function statements are intrinsically explanatory cannot offer a satisfactory account. The account offered by Woodfield, who rejects this assumption, is adequate, though less attractive than the account suggested by the HT. I conclude by considering how the HT can account for functional norms. (shrink)

Three experiments examined whether children and adults would use temporal information as a cue to the causal structure of a three-variable system, and also whether their judgements about the effects of interventions on the system would be affected by the temporal properties of the event sequence. Participants were shown a system in which two events B and C occurred either simultaneously (synchronous condition) or in a temporal sequence (sequential condition) following an initial event A. The causal judgements of adults and (...) 6-7-year-olds differed between the conditions, but this was not the case for 4-year-olds' judgements. However, unlike those of adults, 6-7-year-olds' intervention judgements were not affected by condition, and causal and intervention judgements were not reliably consistent in this age group. The findings support the claim that temporal information provides an important cue to causal structure, at least in older children. However, they raise important issues about the relationship between causal and intervention judgements. (shrink)

In two experiments, we investigated whether 13-month-old infants expect agents to behave in a way consistent with information to which they have been exposed. Infants watched animations in which an animal was either provided information or prevented from gathering information about the actual location of an object. The animal then searched successfully or failed to retrieve it. Infants’ looking times suggest that they expected searches to be effective when—and only when—the agent had had access to the relevant information. This result (...) supports the view that infants’ possess an incipient metarepresentational ability that permits them to attribute beliefs to agents. We discuss the viability of more conservative explanations and the relationship between this early ability and later forms of ‘theory of mind’ that appear only after children have become experienced verbal communicators. (shrink)

Neo-teleology is the two part thesis that, e.g., (i) we have hearts because of what hearts are for: Hearts are for blood circulation, not the production of a pulse, so hearts are there--animals have them--because their function is to circulate the blood, and (ii) that (i) is explained by natural selection: traits spread through populations because of their functions. This paper attacks this popular doctrine. The presence of a biological trait or structure is not explained by appeal to its function. (...) To suppose otherwise is to trivialize natural selection. (shrink)

The two major modern accounts of explanation are the causal and unification accounts. My aim in this paper is to provide a kind of unification of the causal and the unification accounts, by using the central technical apparatus of the unification account to solve a central problem faced by the causal account, namely, the problem of determining which parts of a causal network are explanatorily relevant to the occurrence of an explanandum. The end product of my investigation is a causal (...) account of explanation that has many of the advantages of the unification account. (shrink)

In this paper I discuss recent debates concerning etiological theories of functions. I defend an etiological theory against two criticisms, namely the ability to account for malfunction, and the problem of structural doubles. I then consider the arguments provided by Bigelow and Pargetter (1987) for a more forward looking account of functions as propensities or dispositions. I argue that their approach fails to address the explanatory problematic for which etiological theories were developed.

Biological functions are dispositions or effects a trait has which explain the recent maintenance of the trait under natural selection. This is the "modern history" approach to functions. The approach is historical because to ascribe a function is to make a claim about the past, but the relevant past is the recent past; modern history rather than ancient.

A series of explanatory hypotheses are examined under the assumption that the logical structure of function attributions is dependent on the methodological constraints which these hypotheses conform to. Two theses are argued for: (1) Given these methodological constraints, if something has the function of doing Y, then normally it is the only kind of thing that can do Y in that kind of system. (2) What distinguishes function attributions from causal attribution is not that function attributions explain the etiology of (...) the causally efficacious object, as Wright has suggested. The distinction lies rather in that the object's having the effect, which is attributed to it as its function, must figure in the explanation of why it does what it does to achieve that effect. (shrink)

We examine two approaches to functions: etiological and forward-looking. In the context of functions, we raise the question, familiar to philosophers of mind, about the explanatory role of properties that are not supervenient on the mere dispositional features of a system. We first argue that the question has no easy answer in either of the two approaches. We then draw a parallel between functions and goal directedness. We conclude by proposing an answer to the question: The explanatory importance of nonsupervenient (...) properties (like having the function of doing something, or like being goal-directed) does not lie in any special causal mechanism through which these properties bring about their effects; it lies rather in the different classification of the explananda types that these properties generate. (shrink)