As late as 1870 a Toronto professor, William Hincks, schooled pupils in a circular system of classification. Although his system was derived from Macleay's quinarianism of the 1820s, Hincks had altered it in several ways, influenced by botanical morphology. He persistently promoted it throughout the 1860s as an alternative to Darwinian evolution.

William Sharp Macleay developed the quinarian system of classification in his Horæ Entomologicæ, published in two parts in 1819 and 1821. For two decades, the quinarian system was widely discussed in Britain and influenced such naturalists as Charles Darwin, Richard Owen, and Thomas Huxley. This paper offers the first detailed account of Macleay’s development of the quinarian system. Macleay developed his system under the shaping influence of two pressures: (1) the insistence by followers of Linnaeus on developing artificial systems at (...) the expense of the natural system and (2) the apparent tension between the continuity of organic nature and the failure of linear classification schemes (which continuity seemed to require). Against what he perceived as dogmatic indolence on the part of the Linnaeans, Macleay developed a philosophy of science in which hypotheses that exceeded the available evidence should be proposed and subjected to severe tests. He also developed a novel comparative anatomical methodology, the method of variation, to aid in his search for the natural system. Using this method, he developed an intricate system that showed how organic nature could be continuous without being linear. A failure to appreciate these facets of Macleay’s thought has led to several misunderstandings of him and his work, most notably that he was an idealist. These misunderstandings are here rebutted. (shrink)

British systematics was distinctly marked by a raft of vituperative controversies around the turn of the 1830s. After the local collapse of broad consensus in the Linnaean system by 1820, the emergence of new schemes of classification—most notably, the “quinarian” system of William Sharp Macleay—brought with it an unprecedented register of public debate among zoologists in Britain, one which a young Charles Darwin would bitterly describe to his friend John Stevens Henslow in October 1836 as possessing a “mean quarrelsome spirit,” (...) conducted in “a manner anything but like that of gentlemen.” This article aims to provide a social and conceptual account of the remarkable tenor of zoological discourse in Britain in the late 1820s and early 1830s, with joint attention to the philosophical and interpersonal commitments at play. In doing so, it analyzes the three of the period’s most striking public controversies, each of which counted key advocates of the quinarian system as central participants. (shrink)

Charles Darwin, in his species notebooks, engaged seriously with the quinarian system of William Sharp Macleay. Much of the attention given to this engagement has focused on Darwin’s attempt to explain, in a transmutationist framework, the intricate patterns that characterized the quinarian system. Here, I show that Darwin’s attempt to explain these quinarian patterns primarily occurred before he had read any work by Macleay. By the time Darwin began reading Macleay’s writings, he had already arrived at a skeptical view of (...) the reality of these patterns. What most interested Darwin, as he read Macleay, was not the quinarian system itself. Rather, Darwin’s notes on his reading primarily concerned certain background principles animating Macleay’s work, in particular: the non-existence of a saltus between human and animal minds, the difficulty of establishing boundaries between species and varieties, and Macleay’s method of variation. Darwin’s interest in the last of these left a mark on his discussion of taxonomic methodology in the Origin. (shrink)

Classifications of animals and plants have long been represented by hierarchical lists of taxa, but occasional authors have drawn diagrammatic versions of their classifications in an attempt to better depict the "natural relationships" of their organisms. Ornithologists in 19th-century Britain produced and pioneered many types of classificatory diagrams, and these fall into three groups: (a) the quinarian systems of Vigors and Swainson (1820s and 1830s); (b) the "maps" of Strickland and Wallace (1840s and 1850s); and (c) the evolutionary diagrams of (...) the post-Darwin authors (1860 on). The quinarians distinguished between affinity and analogy and used both in their classifications, whereas Strickland rejected the quinarians' belief in numerical regularity and their use of analogy. Wallace's "maps" are easily given an evolutionary interpretation, and his approach was taken up and modified by later evolutionary anatomists. Sharpe returned to Strickland's methods and merely appended a superficial evolutionary interpretation. Contrary to common belief systematics has a rich conceptual history, and many of the conceptual developments in 19th-century systematics were made by ornithologists. (shrink)