In the decades following the forging of the so-called Neo-Darwinian Synthesis in the 1940s, a number of its philosophical defenders created a myth about what Charles Darwin was up against, a viewpoint called “typological essentialism” often attributed to Aristotle. In this chapter I first sketch the history of how this myth was created. I then establish that it is a myth by providing an account of Aristotle’s essentialism as it is actually displayed in his philosophy of biology and in his biological practice. It has nothing to do with the ‘mythic’ version. We then turn to what Darwin was really up against—a creationist anti-evolutionary way of defining the species concept that was common in Darwin’s time (that owes nothing to Aristotle), and to his attempts to re-orient thinking about it. I will close by reconsidering Aristotle and Charles Darwin: Does it make any sense to think about the relationship between two thinkers separated by more than two millennia living in such vastly different cultures? What did Charles Darwin himself think about Aristotle?

Interpreters often cite Kant’s Stufenleiter of representations (A320/B376) as providing a “definition” of intuition. This misunderstands the peculiar logic of Porphyrian classification, which I clarify by reviewing its history. Porphyrian trees do offer conceptual analyses, I argue, but do not purport to provide a uniquely correct, much less exhaustive, account of the analysand. Different orderings of differentia, as well as different differentia, are often possible. Which terms and which kinds of terms appear as differentia in the analysis depends on the goals and constraints on the philosophical inquiry to which the analysis contributes. It is therefore illegitimate to extract a “definition” of intuition from Kant’s Stufenleiter. First, its analysis targets <idea of reason> (not <intuition>), and, second, it does not purport to give a uniquely correct account of that concept (much less of <intuition>), as a definition must.

● Pheneticism, evolutionary taxonomy, and cladistics are competing taxonomic philosophies; they disagree about how the classification of a group of organisms and the genealogies of those organisms are related. The cladistic approach is defended. ● It is widely agreed that it is a matter of convention whether a set of species should be placed into a single genus or into more than one. The point generalizes – superspecific taxonomic rank is a matter of convention. ● It is a separate question whether it is conventional matter whether a set of organisms comprises one species rather than several. ● The view is defended that biological taxa are spatio-temporally extended physical objects; they are “individuals,” not natural kinds. ● The question is explored of whether human races are biologically real. ● Cladistic parsimony is explained; it is a method for inferring phylogenies that differs from the method of maximum likelihood. ● The question is raised as to whether parsimony should be evaluated by using the law of likelihood; an alternative is explored – that both methods should be evaluated by seeing whether they are statistically consistent.

This chapter defines a genre of lyric whose speaker is a personification of an entire species. Lyrics of this kind appear in poetic field guides in the 1830s, and in poetry for children throughout the century. The chapter closes with readings of lyrics by Swinburne and Hardy in which the conditions under which a species can become a speaking subject are opened to critique

Chapter two is dedicated to the complicated contemporary debate on the notion of biological species. After a short introduction and critical analysis of all major relational and intrinsic definitions of species, special attention is paid to the recent revival of the essentialist species concept, both in its contemporary and classical Aristotelian-Thomistic formulations, tested against the two major arguments denying their compatibility with evolutionary biology.

“In the early eighteenth century, Britain sought to establish itself as the centre of a global knowledge network and, as part of its imperial ambitions, all of nature was subjected to scientific scrutiny and potential control. Swift’s protagonist Lemuel Gulliver recognises his potential as a broker of knowledge within numerous transnational, transcultural, and trans-species encounters, padding his empirical, observational prose with enumeration and comparison in order to convey information about supposedly faraway lands and peoples. Swift’s vignettes of interspecies or intercultural viewing ironise the colonial contact zone, revealing the partiality, contingency, and relative value of British and European scientific knowledge, and, ultimately, undermining notions of national or racial superiority upon which visions of empire rest. Gulliver’s Travels is itself a remarkable encounter, between literature and science, and the parameters of that engagement are partly defined by the colonial project, with the seemingly objective activity of observation implicated in imperial tyranny and exploitation. In scientific observation, Swift found a discursive mode around which he could structure an entire prose satire whilst also probing its intellectual and moral limits, placing the process of observation itself under satiric scrutiny.”

The primary assumptions and formulations for single-phase flow regimes are reviewed in this chapter. This includes the governing partial differential equations for general fluid dynamics (mass, momentum, energy, and species), equations of state and associated flow regimes, rotational effects and the stream function for incompressible flow, and viscous effects with the Reynolds number, including flow instability mechanisms.

This chapter tracks the figure of the rat across American short fiction, focusing in particular on H. P. Lovecraft’s “The Rats in the Walls” (1924), Ursula K. Le Guin’s “Mazes” (1975), and Karen Joy Fowler’s “Us” (2013). These stories illustrate powerful narrative effects that can be produced by constructing particular forms of animality, while also blurring, at times, the boundaries between what it means to be a human and what it means to be an animal. The chapter engages with the academic fields of human–animal studies, multispecies studies, and animality studies, exploring the short stories not only in relation to animal advocacy, but also problematic histories of animalizing certain human groups. Posthumanism cuts across these various fields, questioning constructions of the human as fundamentally different and superior to all other species on the planet. The chapter ultimately argues that some narrative techniques have more posthumanist potential than others.

In this chapter, I explore the role of the concept of inner purposiveness in the final section of Hegel’s Logic and also the Philosophy of Nature. Hegel defends the claim that the concept is meaningfully applied to living organisms, particularly animals. The concept is actually used precisely where we should expect it, given the argument of ‘Teleology’, both when talking about the internal organisation of animals in parts-organs and when talking about the self-repair or regeneration processes by which they stay alive. By contrast, the concept no longer dominates the description of the natural process that Hegel designates ‘process of the genus’ (or ‘generic process’), in which he considers that natural life is ultimately submitted to externality. I argue that this application and lack of application taken together confirm my views on ‘Teleology’.

Every textbook of biology will supply a number of ‘modes of speciation’, the ways in which new species evolve. But the issues in dispute among the biologists themselves are rather odd. The adoption of evolutionary theory by biologists has had a great impact on how species are understood. From the idea that kinds of living beings were created and at best had devolved to localised varieties, now species were the target of a ‘mechanical’ or ‘physiological’ explanation: they came into being. And under Darwin’s version of the evolutionary account (initially known as the ‘development theory’, since the Latin word evolutio means ‘development’), species were made from other, allied (which means ‘closely related’), species. The processes and causes of new species set up the ‘species question’ that Darwin and other naturalists were seeking to answer.

What are species worth? Do they have inherent value or are they just of value to human beings? Do they have rights? Does their integrity as species have moral worth, and do we have a duty to preserve them, or to modify them? Are species of utilitarian or instrumental value? These are the questions that the third great topic of philosophy seeks to answer: axiology – the values of things, and the duties they impose upon us as ethical, economic and aesthetic beings.

For a long time, species have been thought to be the index marker for healthy ecosystems, for undisturbed nature and for conservation, but the reasons why have varied considerably. National Parks developed from a desire to maintain potential sources of timber, game and hunting opportunities in the United States at the end of the nineteenth and the turn of the twentieth century, as demonstrated in Teddy Roosevelt’s book The Wilderness Hunter; An Account of the Big Game of the United States and Its Chase with Horse, Hound, and Rifle.

It’s not enough to just list the clusters in the living world. One also needs to group clusters together within larger clusters. This process is sometimes referred to as ‘ordering the world’, and is called taxonomy, from the Greek word for ‘order’, taxis. In traditional taxonomy, begun in the sixteenth and seventeenth centuries, and formalised in the eighteenth century by Carl Linnaeus, this meant that species were grouped together in groups called in Latin genera (that’s the plural; the singular is genus). As a result, Linnaeus gave each species a two-part name (a binomial): its genus name (which always has a capital initial) and its species ‘epithet’ (which is always in lowercase). So, our species binomial is Homo sapiens; we are the species sapiens in the genus Homo. It’s kind of like a street address – you have the ‘general’ name (the ‘street’) and the ‘specific’ name (the ‘house number’) (see Box 2.1)

There are several ‘enigmatic canid’ species in North America. One of them is the red wolf (Canis rufus, Figure 1.1), and another is the Great Lakes Wolf. Red wolves are seriously endangered, with a re-released population in North Carolina and breeding programmes being the last populations. Red wolves weren’t even studied closely until the 1960s, after having been hunted nearly to extinction in the nineteenth and twentieth centuries.

The title of this book is Understanding Species, and I have spoken at length about what we understand species to be and to mean. Now, though, I would like to ruminate for a bit on the ‘understanding’ part.

To understand something is not necessarily to have the One True Answer. Human knowledge, and especially its concepts, is in a state of flux at all times. Sometimes, this is because we are learning new things about what the concept refers to, as is the so-called rule in science (it sometimes isn’t). At other times it is because the concept no longer means anything (like ‘phlogiston’ in chemistry or ‘vital force’ in biology). But sometimes it is because the concept has been included into the ‘what everybody knows’ segment of culture. John Maynard Smith, a famous and influential British evolutionary biologist, called this the Bellman’s Theorem (from Lewis Carroll’s The Hunting of the Snark): ‘what I tell you three times is true’.

As I have noted, terms for species are at best polysemic (that is, they are a single word in a language with multiple and often incompatible meanings), and at worst species is a term with no meaning of any real scientific importance. Now we will consider several replacement concepts, and the evolutionary and genetic considerations that make them seemingly viable.

In Chapter 2 we considered the extent of the different definitions as applied to a simplified version of human evolution and genetics. One of those definitions included a historical aspect – monophyly.

If there is an issue in a science, philosophers will attend to it. This is not new, either. Since the rise of modern science in the seventeenth century, many if not most of the problems that philosophers have addressed or formulated have arisen out of science one way or another. Books on ‘the philosophy of botany’ or ‘the philosophy of natural history’ were published from the late eighteenth century onwards, although ‘philosophy’ meant knowledge in those days, and included scientific thinking. Nevertheless, science has always been a productive source of new problems for philosophy to chew on.

One of the things that is often said about the frankly catastrophic loss of biodiversity in the world today is that extinction is a natural process of the living world, and this is quite true. Extinction does not naturally occur at a constant rate, however. It ranges from near instantaneous (as when a 12-km-wide rock hits the planet, causing a Very Bad Day for most living things) to a slow background rate of extinction of species that have been reduced to a relic of past distributions and population numbers. So, when those who do not think we are in a catastrophic situation say, ‘Extinction is natural’, point out to them that the present scale of extinction is in global terms worse than a 12-km bolide, at least in geological terms, for the geological record doesn’t distinguish easily between a one-day catastrophe and a four-century one. Both are ‘sudden’ events in Deep Time. As E. O. Wilson wrote, in his book The Diversity of Life (1992)

There are, says Professor Julia Sigwart, an American mollusc specialist (malacologist), species makers and species users. The former are the taxonomists, and they identify, name and record species in technical journals and store the type specimens (the original specimen that ‘bears’ the name) in museums and other collections. There are way too few of these. The latter – well, that includes everybody, according to Sigwart. She notes in her 2019 book What Species Mean (chapter 3) that looking out of her window she sees species of tree, animal, bird and other living things, and that this knowledge involves two main steps: knowing that something is different from other similar (or related) things; and giving it a unique name to communicate and identify it to other users, for the taxonomists are also users of species. Knowing and naming species are related activities, but not the same.