With the debate between Richard Owen and Thomas Huxley on the differences between the ape and human brains as its focus, this book explores some of the ways in which philosophical ideas and scientific practice influenced the discussion of evolution in the years before and after Darwin's publication of Origin of Species in 1859. It also shows how this episode can shed light on current philosophical notions of scientific practice and how they in turn influence our understanding of the history of science. The book advances the current historical discussion of the Owen-Huxley debate by making clear that Owen's anatomical claims had much more support than most historians and philosophers of science assume.
One vital way Owen and Huxley differed in their approach to anatomy was how they handled absolute brain size. Owen argued that because the average human brain size was more than double the size of the record ape brain, absolute brain size distinguished humans from apes. Huxley by contrast, argued that because you can find a hippocampus minor in both ape and human brains, there was no great difference. In his 1863 book, Huxley had the artist make a human and chimpanzee brain the same length so that they appear similar size. But if the brain of a full grown chimpanzee is compared at the same scale with a fully grown human brain, the absolute brain size of human is as large as Owen insisted in the debate.
Owen's Ape and Darwin's Bulldog also seeks to explore differences in how Owen and Huxley approached racial issues in their debate as a case study on the interplay between values and laboratory science. Beginning in his 1835 paper and throughout the debate Owen maintained that all racial groups have similar brain sizes and intellectual abilities. By contrast, Huxley argued that African brains were intermediate between Europeans and apes: "if we place A, the European brain, B, the Bosjesman brain, and C, the orang brain, in a series, the differences between A and B, so far as they have been ascertained, are of the same nature as the chief of those between B and C."