Evolutionary ethics, the idea that the evolutionary process contains the basis for a full and adequate understanding of human moral nature, is an old and disreputable notion. It was popularized in the 19th century by the English general man of science, Herbert Spencer, who began advocating an evolutionary approach to ethical understanding, even before Charles Darwin published his Origin of Species in 1859 (Spencer 1857, 1892). Although it was never regarded with much enthusiasm by professional philosophers, thanks to Spencer’s advocacy the evolutionary approach to ethics soon gained wide popularity, both in Britain and towards the end of the century, even more in the United States of America (Ruse 1986; Russett 1976). It became transformed into a whole sociopolitical doctrine, known somewhat inaccurately as ‘Social Darwinism.’ (Scholars have long debated as to whether Darwin himself was truly a Social Darwinian, and the answer seems to depend on which of his works you read. If you look at the Origin of Species, he certainly is not. On the other hand, if you look at the Descent of Man, there are good reasons for thinking that he was not unsympathetic to the idea.

In this paper I want to clarify what biologists are talking about when they talk about the evolution of altruism. I’ll begin by saying something about the common sense concept. This familiar idea I’ll call ‘vernacular altruism.’ One point of doing this is to make it devastatingly obvious that the common sense concept is very different from the concept as it’s used in evolutionary theory. After that preliminary, I’ll describe some features of the evolutionary concept. Then I’ll conclude by briefly considering what explanatory relation might obtain between vernacular altruism and evolutionary altruism.

Although the points I’ll make are rather elementary ones, their interest is not restricted to those who have never heard of the evolutionary problem. The reason for this is that there is some amount of confusion about evolutionary altruism among evolutionary biologists themselves.

Molecular biology has as its primary objective the elucidation of the coupling between genotype and phenotype. This goal has so far been pursued within a neoDarwinian theoretical framework which is relatively limited. Within this framework we can indeed understand remarkably well the mechanisms of replication and expression of genes and the means by which replication and expression are regulated in cells; we know how genotype determines phenotype at the molecular level, in single cells. We are also close to an understanding of the relationship between genes and development in muticellular animals and plants.

Q: What did the elephant say to the naked man?

A: It looks O.K., but can you breathe through it?

Let me begin by justifying that joke for those of you didn’t find it funny. The relationship between the morphology of the physical organs and their activities has long been a vexed issue in the philosophy of biology: the question of whether structure determines function is of course of contemporary importance in evolutionary theory. That there was a relationship between structure and function was not in general a matter of doubt to the Greek theoretical biologists: but both the extent, and crucially the direction, of the dependence was. And the question need not be restricted to a consideration of the function of a particular part in isolation: when Aristotle takes issue with Anaxagoras for asserting that humans are the most intelligent species because they have hands, claiming rather that they have hands because they are intelligent, he is making a claim not just about the direction of explanation involved, but he is also implicitly at least indicating the scope of such explanations. For Aristotle, intelligence is one of the human functions: and that function necessitates the existence and development of certain organic structures.

In 1973 Niels Kaj Jerne announced an important new hypothesis about the immune system (‘IS’). That suggestion is based on several similarities between IS and the central nervous system. Jerne postulated that IS, like the nervous system, is a network.

This proposal has a number of implications, including some philosophical ones. Here I focus on the question whether the network hypothesis and subsequent developments shed any light on the use of teleological concepts in biology. In part one I present some of the background story of network ideas in immunology, including a reverse hypothesis to the effect that IS-Net could serve as a basis for modeling the brain. In part two I locate the teleological implications of IS-Net with respect to current mainstream discussions of teleology.

In The Structure of Biological Science (Rosenberg [1985]) I argued that the theory of natural selection is a statistical theory for reasons much like those which makes thermodynamics a statistical theory. In particular, the theory claims that fitness differences are large enough and the life span of species long enough for increases in average fitness always to appear in the long run; and this claim, I held, is of the same form as the statistical version of the second law of thermodynamics.

For the latter law also makes a claim about the long run, and its statistical character is due to this claim: thermodynamic systems must in the long run approach an equilibrium level of organization that maximizes entropy. Over finite times, given local boundary conditions, an isolated mechanical system, like the molecules in a container of gas, may sometimes interact so as to move the entropy of the system further from, instead of closer to the equilbrium level. But given enough interacting bodies, and enough time, the system will always eventually move in the direction prescribed by the law. Thus, we can attach much higher probabilities to the prediction that non-equilibrium systems will reflect greater entropy in future periods than we can to predictions that they will move in the opposite direction. And as we increase the amount of time and the number of bodies interacting, the strength of the probability we can attach to the prediction becomes greater and greater.

Supervenience is a relationship which has been used recently to explain the physical determination of biological phenomena despite resistance to reduction (Rosenberg, 1978, 1985; Sober, 1984a). Supervenience, however, is plagued by ambiguities which weaken its explanatory value and obscure some interesting aspects of reduction in biology. Although I suspect that similar considerations affect the use of supervenience in ethics and the philosophy of mind, I don’t intend anything I have to say here to apply outside of the physical and biological cases I consider.

The main point of this paper is that there is a property of biological systems which makes it both misleading and inappropriate to reduce central biological phenomena to the properties of underlying components. Despite this, reductive explanation has been a major source of innovation in biological theory. The apparent tension can be resolved if underlying properties are explanatorily relevant to the higher level phenomena even though the latter are not strictly reducible to the former. Supervenience, I will argue, is not robust enough to deny reduction while supporting explanatory relevance.

The implications of evolutionary theory for a theory of knowledge have been explored by numerous writers in the period since Darwin. (See, for example: Spencer [1857]; Toulmin [1967, 1972]; Popper [1965, 1972, 1974]; Campbell [1974].) In general, these writers have developed theories of knowledge development by analogy with evolutionary theory. That is, they have developed theories which apply the mechanism of differential selection on variation to the growth of knowledge. In this sense knowledge is seen to be a function of success (often understood in pragmatic terms) in a field of alternative ideas. Knowledge evolves in much the same way as organisms with more robust ideas or ideas with greater verisimilitude or greater explanatory power or greater problem solving ability, etc. surviving from one generation to the next in the struggle for acceptance. Hence, the title ‘evolutionary epistemology.’

One of the admirable purposes of the current anthology is to attempt a dialogue between professional philosophers of biology and biological scientists. This is indeed an ambitious undertaking, because although the former group pays a lot of attention to the latter, active scientists rarely pay heed to what the philosophers of biology, or even of science in general, have to say. The current paper is an attempt to address some reasons why this might be so from the bench-level view of a biological scientist who has only a superficial acquaintance with the philosophy of science. Any excursion out of the confines of one’s professional discipline, such as the current one, generates the healthy fear that the exercise will end up in humiliation for the fool who attempts it. I have, perhaps foolishly, overcome this fear in the spirit of this symposium, with the hope that my more glaring errors of interpretation of the philosophy of science will be forgiven by the professional philosophers reading this paper, in the interest of establishing a dialogue.