The essays are divided into three sections. The first is about evolution, and the three essays it contains are all attacks on the adaptionist, neo-Darwinian view of the subject. The essays are lucid and well argued (as one would expect from the author of The Genetic Basis of Evolutionary Change) but there is a bit of repetition between them (two of them were originally encyclopaedia articles on "Evolution" and "Adaption"). The second section, entitled "On Analysis", contains a warning of the potential for misuse of the analysis of variance in genetics, the parody "Isadore Nabi on the Tendencies of Motion", and an essay on the relationship between dialectics and reductionism which makes particular reference to community ecology.
The third section, entitled "Science as a Social Product and the Social Product of Science", contains an eclectic collection of essays on the use of science and the effects of social factors on science. The essay titles here are "Lysenkoism", "The Commoditization of Science", "Biology in the Third World", "Political Economy of Agricultural Research", "The Pesticide System", "Research Needs for Latin Community Health" and "What is Human Nature?". The essay on Lysenkoism was the one I found the most interesting; while not denying the scientific errors involved, it is concerned to explain the full complexities of the "affair", which are all too often ignored by those using it as a stick to beat Marxism with. The common feature of all the essays is respect for the complexities of social processes, scientific practice and the interaction between them.
The conclusion is a short (around twenty page) general discussion on the philosophical foundations of science entitled "Dialectics". It is one of the best things I have ever read on the philosophy of science, and a worthy conclusion to a great book. The Dialectical Biologist is heartily recommended to anyone with an interest in biology or the philosophy of science.