- As working scientists in the field of evolutionary genetics and ecology, we have been attempting with some success to guide our own research by a conscious application of Marxist philosophy. We therefore cannot accept the view that philosophy must (or can) be excluded from science, and deplore the anti-ideological technocratic ideology of Soviet liberals. At the same time, we cannot dismiss the obviously pernicious use of philosophy by Lysenko and his supporters simply as an aberration, a misapplication, or a distortion dating from the era that is often brushed aside as 'the cult of personality' (with or without naming the personage in question). Nor is it sufficient to note that Marxism has had its signal successes despite Lysenko, with its pioneering work in the origin of life among its achievements. Unless Marxism examines its failures, they will be repeated.
- "The Problem of Lysenkoism" by Richard Lewontin and Richard Levins in Hilary and Steven Rose (eds.), The Radicalisation of Science, Macmillan pb, 1976, pp. 32–64
- The great attraction of cultural anthropology in the past was precisely that it seemed to offer such a richness of independent natural experiments; but unfortunately it is now clear that there has been a great deal of historical continuity and exchange among those "independent" experiments, most of which have felt the strong effect of contact with societies organized as modern states. More important, there has never been a human society with unlimited resources, of three sexes, or the power to read other people's minds, or to be transported great distances at the speed of light. How then are we to know the effect on human social organization and history of the need to scrabble for a living, or of the existence of males and females, or of the power to make our tongues drop manna and so to make the worse appear the better reason? A solution to the epistemological impotence of social theory has been to create a literature of imagination and logic in which the consequences of radical alterations in the conditions of human existence are deduced. It is the literature of science fiction. ... [S]cience fiction is the laboratory in which extraordinary social conditions, never possible in actuality, are used to illumine the social and historical norm. ... Science fiction stories are the Gedanken experiments of social science.
- "The Last of the Nasties?" in New York Review of Books (2/29/96)
- review of The Lost World by Michael Crichton
- The fallacy of genetic determinism is to suppose that the genes "make' the organism. It is a basic principle of developmental biology that organisms undergo a continuous development from conception to death, a development that is the unique consequence of the interaction of the genes in their cells, the temporal sequence of environments through which the organisms pass, and random cellular processes that determine the life, death, and transformation of cells. As a result, even the fingerprints of identical twins are not identical. Their temperaments, mental processes, abilities, life choices, disease histories, and death certainly differ despite the determined efforts of many parents to enforce as great a similarity as possible.
- "The Confusion Over Cloning" in New York Review of Books (10/23/97)
- review of Cloning Human Beings: Report and Recommendations of the National Bioethics Advisory Commission
- We have a prior commitment, a commitment to materialism ... we cannot allow a Divine Foot in the door.
Sex, Lies, and Social Science (1995) 
- "Sex, Lies, and Social Science" in New York Review of Books (4/20/95)
- The social scientist is in a difficult, if not impossible position. On the one hand there is the temptation to see all of society as one's autobiography writ large, surely not the path to general truth. On the other, there is the attempt to be general and objective by pretending that one knows nothing about the experience of being human, forcing the investigator to pretend that people usually know and tell the truth about important issues, when we all know from our lives how impossible that is. How, then, can there be a "social science"? The answer, surely, is to be less ambitious and stop trying to make sociology into a natural science although it is, indeed, the study of natural objects. There are some things in the world that we will never know and many that we will never know exactly. Each domain of phenomena has its characteristic grain of knowability. Biology is not physics, because organisms are such complex physical objects, and sociology is not biology because human societies are made by self-conscious organisms. By pretending to a kind of knowledge that it cannot achieve, social science can only engender the scorn of natural scientists and the cynicism of the humanists.
- It is characteristic of the design of scientific research that exquisite attention is devoted to methodological problems that can be solved, while the pretense is made that the ones that cannot be solved are really nothing to worry about. On the one hand, biologists will apply the most critical and demanding canons of evidence in the design of measuring instruments or in the procedure for taking an unbiased samples of organisms to be tested, but when asked whether the conditions in the laboratory are likely to be relevant to the situation in nature, they will provide a hand-waving intuitive argument filled with unsubstantiated guesses and prejudices because, in the end, that is all they can do.
- The division between those who try to learn about the world by manipulating it and those who can only observe it had led, in natural science, to a struggle for legitimacy. The experimentalists look down on the observers as merely telling uncheckable just-so stories, while the observers scorn the experimentalists for their cheap victories over excessively simple phenomena. In biology the two camps are now generally segregated in separate academic departments where they can go about their business unhassled by their unbelievers. But the battle is unequal because the observers' consciousness of what it is to do "real" science has been formed in a world dominated by the manipulators of nature. The observers then pretend to an exactness that they cannot achieve and they attempt to objectify a part of nature that is completely accessible only with the air of subjective tools.
- a reply to critical comments on his article "Sex, Lies and Social Science" in New York Review of Books (4/20/95)]
Letter to the editor, 1995 
- Letter to the editor, New York Review of Books (11/2/95)
- [T]he psychic and physical characteristics of human beings, and the differences between individuals, are the consequence of an interaction between the genes that are present in the fertilized egg and the sequence of environmental circumstances that the developing organism experiences during its life cycle. With a few exceptions ... human characteristics are all subject to this interaction of forces. There are, morever, random events in cell growth and differentiation that are neither genetic nor environmental in the usual sense, and which play an extremely important part in development, especially in behavioral traits.
An important consequence of the unique interaction between internal and external forces ... is that knowledge of genetic differences contain no information at all about whether a characteristic can be changed by environmental and social arrangements. The most elementary error about genetics and development is to suppose that "genetic" is the opposite of "changeable" and that an answer to the question "how much can a trait be changed by social, historical and individual circumstances" is given by an answer to the question "how important are genes."
- Genetics is the study of similarity between relatives, and the problem of human genetics is that, in a species with a family and social structure and a taboo against manipulating individual life histories experimentally, there is a confounding between the similarity of relatives that arises from biological causes and the similarity that arise from social causes.
- To say that genetic differences are relevant to hetero- and homosexuality is not, however, to say that there are "genes for homosexuality" or even that there is a "genetic tendency to homosexuality." This critical point can be illustrated by an example I owe to the philosopher of science, Elliott Sober. If we look at the chromosomes of people who knit and those who do not, we will find that with few exceptions, knitters have two X chromosomes [women], while people with one X and one Y chromosome [men] almost never knit. Yet it would be absurd to say that we had discovered genes for knitting. ... [I]n our culture, women are taught to knit and men are not. The beauty of this example is its historical (and geographical) contingency. Had we made our observations before the end of the eighteenth century (or even now in a few Irish, Scottish and Newfoundland communities), the results would have been reversed. Hand knitting was men's works before the introduction of knitting machines around 1790, and was turned into a female domestic occupation only when mechanization made it economically marginal.