This article argues that Brentano’s classification of mental phenomena is best understood against the background of the theories of natural classification held by Auguste Comte and John Stuart Mill. Section 1 offers a reconstruction of Brentano’s two-premise argument for his tripartite classification. Section 2 gives a brief overview of the reception and historical background of the classification project. Section 3 addresses the question as to why a classification of mental phenomena is needed at all and traces the answer back to (...) Mill’s view that psychological laws are class-specific. Section 4 and 5 connect the second premise of Brentano’s argument to Comte’s principle of comparative likeness and Mill’s insistance that class membership is determined by the possession of common characteristics. And section 6 briefly discusses the evidence Brentano provides for the first premise. (shrink)

Thomas Henry Huxley and Charles Darwin discovered in 1857 that they had a fundamental disagreement about biological classification. Darwin believed that the natural system should express genealogy while Huxley insisted that classification must stand on its own basis, independent of evolution. Darwin used human races as a model for his view. This private and long-forgotten dispute exposes important divisions within Victorian biology. Huxley, trained in physiology and anatomy, was a professional biologist while Darwin was a gentleman naturalist. Huxley agreed with (...) John Stuart Mill's rejection of William Whewell's sympathy for Linnaeus. The naturalists William Sharp Macleay, Hugh Strickland, and George Waterhouse worked to distinguish two kinds of relationship, affinity and analogy. Darwin believed that his theory could explain the difference. Richard Owen introduced the distinction between homology and analogy to anatomists, but the word homology did not enter Darwin's vocabulary until 1848, when he used the morphological concept of archetype in his work on Cirripedia. Huxley dropped the word archetype when Richard Owen linked it to Plato's ideal forms, replacing it with common plan. When Darwin wrote in the Origin of Species that the word plan gives no explanation, he may have had Huxley in mind. Darwin's preposterous story in the Origin about a bear giving birth to a kangaroo, which he dropped in the second edition, was in fact aimed at Huxley. (shrink)

A dominant strand of philosophical thought holds that natural kinds are clusters of objects with shared properties. Cluster theories of natural kinds are often taken to be a late twentieth-century development, prompted by dissatisfaction with essentialism in philosophy of biology. I will argue here, however, that a cluster theory of kinds had actually been formulated by William Whewell (1794-1866) more than a century earlier. Cluster theories of kinds can be characterized in terms of three central commitments, all of which are (...) present in Whewell’s work on classification. Like contemporary cluster theorists, Whewell claims that kinds are united by similarity, that many kinds do not have essences, and that there are “gaps” between kinds. Moreover, Whewell advises taxonomists to look for consilience (roughly, convergence) between different classificatory schemes, a recommendation that reinforces the identification of natural classes with property clusters. Thus Whewell was not only an early cluster theorist, but one with important insights into what a cluster theory of kinds means for the practice of classification. (shrink)

Alexander Moritzi is one of the most obscure figures in the early history of evolutionary thought. Best known for authoring a flora of Switzerland, Moritzi also published Réflexions sur l’espèce en histoire naturelle, a remarkable book about evolution with an overtly materialist viewpoint. In this work, Moritzi argues that the generally accepted line between species and varieties is artificial, that varieties can over time give rise to new species, and that deep time and turnover of species in the fossil record (...) clearly support an evolutionary interpretation of biological diversity. Moritzi was also a gradualist and viewed relationships between taxa as best represented by a ramifying tree. Although Réflexions was the first full book to be written on the topic of evolution following Lamarck’s Philosophie zoologique, Moritzi’s evolutionist contribution was stillborn, read by almost no one in his lifetime and ultimately absent from the many historiographies of evolutionary thought. This is unfortunate since many of the arguments Moritzi marshaled on behalf of an evolutionary explanation of life can be found in subsequent transmutationist writings by Frédéric Gérard, Robert Chambers, Henri Lecoq, Baden Powell, Charles Naudin, Herbert Spencer, Alfred Russel Wallace, and Charles Darwin—none of whom is likely to have ever known of the existence of Réflexions. Finally, Moritzi’s arguments, along with those found in Darwin’s private essay on evolution of the same year, provide an excellent window into the state of evolutionary thought and debate over the nature of species at the beginning of the 1840s. (shrink)

Scientists represent their world, grouping and organizing phenomena into classes by means of concepts. Philosophers of science have historically been interested in the nature of these concepts, the criteria that inform their application and the nature of the kinds that the concepts individuate. They also have sought to understand whether and how different systems of classification are related and more recently, how investigative practices shape conceptual development and change. Our aim in this paper is to provide a critical overview of (...) some of the key developments in this philosophical literature and identify some interesting issues it raises about the prospects of the so-called “special sciences”, including psychiatry, psychology, and the mind-brain sciences more generally, to discover natural kinds. (shrink)