Ernst Haeckel (1834–1919) remains one of the most controversial and divisive figures in the history of biology. Haeckel's influence is indisputable; he became an early convert to Charles Darwin's teachings and subsequently styled himself into the role of the Messiah of Darwinism. In this role he proved to be particularly successful; far more people learned of descent with modification through Haeckel than through any other person, including through Darwin himself. Haeckel also combined the realm of the aesthetic with science; he skilfully, but maybe not always truthfully, documented the endless creativity of natural forms and influenced the aesthetic sense of an entire era. Haeckel also, however, represents to many scientists and historians the ugly side of evolutionary speculation – he had, for example, apparently no reservations about arranging different groups of extant humans by their distance from an ape ancestor and he has again and again been seen as an key intellectual forefather of Nazi ideology. Historians who do not support this assertion still often suspect that Haeckel was not a ‘real’ Darwinist because he allegedly stuck all his life to the outdated doctrines of idealist morphology. In the single person of Haeckel we thus find damning judgements both on pre-Darwinian biology and on alleged scientific and political deviations from orthodox Darwinism, and this unsatisfying state of affairs calls for a fundamental re-examination. The two books under review take on this task, but employ radically different strategies. Sander Gliboff's concise and demanding, but nonetheless elegant and persuasive, book offers a refreshingly revisionist perspective on pre-Darwinian German biology, on Heinrich Georg Bronn's notorious first translation of Darwin and on Haeckel's attempts to reconcile ontogeny and phylogeny. In contrast, Robert J. Richards, in his characteristically exuberant prose, offers a full picture of Haeckel's charismatic personality and his passionate and tragic private and professional life. In political history, the thesis of the German Sonderweg has long been in decline – both Gliboff and Richards manage to make German biology in the nineteenth century appear far less peculiar than usually is the case.

Gliboff challenges a historiographical tradition that portrays pre-Darwinian German biology as following a strictly typological, linear recapitulationism that is wholly incompatible with Darwinism. Gliboff's close reading of the works of Johann Friedrich Meckel and Carl Friedrich Kielmeyer shows, however, that these scientists were far less rigid and typological than influential historians such as E.S. Russell, Erik Nordenskiöld or Stephen Jay Gould have maintained. These early biologists endeavoured to account both for law-like patterns and for the undeniable variability of nature. The naive linear recapitulationism ascribed to them is, according to Gliboff, a caricature instigated by Karl Ernst von Baer and later uncritically adopted by many historians and biologists. Gliboff clarifies that recapitulation and the type concept as employed by German biologists were not straitjackets, but were able to account for variation and adaptation. The bridge between the old and new biology was H.G. Bronn, Darwin's first translator. He was a very practically oriented palaeontologist and geologist, who could appreciate both the German tradition in biology and Darwin's revolutionary new ideas. Bronn had to translate a work that was steeped in Victorian culture and did not conform at all to the rhetoric and form of German Wissenschaft, a science organized around systematic, universal laws. Gliboff shows convincingly that Bronn's translation of ‘selection’ with Züchtung was an attempt to translate the ambiguities he found in Darwin's work and that Vervollkommnung – a perfectly legitimate translation of Darwin's ‘perfection’ – was meant as a relative term describing a better adaptation to the environment. In his last chapter Gliboff describes Haeckel as a serious scientist who tried to understand the relationship between heredity and variation and thus contributed to the – still ongoing – transformation of Darwinism. The early twentieth century was characterized by a broad landscape of Darwinian theories and to label Haeckel un-Darwinian is Whiggish and unjust. Gliboff's study is without doubt one of those rare events that will stimulate many readers to fundamentally reassess their stance towards a major episode in the history of science.

Robert J. Richards's long-awaited biography of Haeckel is revisionist as well, but in a very different sense than is Gliboff's study. Richards adeptly interweaves Haeckel's life as a private person, polemicist and scientist with cultural history and politics. One single fateful day in Haeckel's life offers Richards the means to bring together the disparate elements of the protagonist's personality. On 16 February 1864 Haeckel turned thirty, he was awarded the Cothenius-Medal of the Leopoldina, and his beloved wife Anna Sethe died. From then on Haeckel only found solace and distraction in the compulsive study of nature, where he saw lack of meaning, violence and transience, but also a source of unimaginable beauty. Like Gliboff, Richards stresses Haeckel's scientific accomplishments, but he devotes considerable space to his artistic achievements and his public persona. Richards succeeds in painting a full and compelling picture of all aspects of Haeckel's life and expends considerable energy in trying to absolve Haeckel from all the charges laid against him.

Given the excessive condemnation that Haeckel has suffered in the history of biology, the sometimes hagiographic undercurrents in Richards's account can perhaps be understood, but at some points more critical distance could have been wished for. Haeckel certainly was not a direct source of the racial ideology of the Nazis. In political history, however, such direct and clearly identifiable causal influences do not carry as much weight as they used to. Haeckel participated in, and scientifically legitimized, a discourse that supported racist and anti-Semitic ideas. He was certainly not unique in that respect, but any critical history has to confront this fact. Furthermore, Haeckel's fanatical anti-Catholicism is mainly explained through his personal experience, while the bitter fight of Bismarck against the influence of the Catholic Church – the Kulturkampf – remains tangential. In Richards's account Haeckel becomes the true heir of Goethe's legacy, while he actually might be better understood as one of the contradictory intellectual figures who are so characteristic of imperial Germany. But despite these reservations, Robert Richards has also written a book that no historian of biology can afford to ignore.