The reception of Wagner’s music as physically affecting, sound that manipulates the bodies of listeners, took place within a context of research into human and animal physiology. From reflex mechanisms to sense energies, the physiological response to art brought about new understandings of ‘physiological aesthetics’ in figures from Herbert Spencer to Thomas Huxley and Francis Galton, with a corresponding ‘physiological music theory’ applied by Ernst Mach and Hermann von Helmholtz. This led to various efforts at quantification of ear acuity and the role of the auditory nerve.

In the shadow of decadence, critical evaluation of works like Tristan and Tannhäuser traverse the spectrum from appreciation (‘bliss of the spinal cord’) to anxiousness (‘Wagner increases exhaustion’). Against these claims, Wagner’s numerous writings on sentience (Sinnlichkeit), rooted in Ludwig Feuerbach’s philosophy of perceptual realism, were directed towards topics as diverse as a theory of performance, the role of critics, and animal testing.

This chapter studies two contrasting models for predictive thinking and representation in Thomas Hardy. In The Return of the Native (1878), Hardy’s depiction of repetitive phenomena evokes one renovated account of logico-mathematical probability, John Venn’s empirical theory about how we judge from series of instances. In the novel’s palpably antiquated rural setting – where characters intuit more than they see, gamble by the light of glowworms, and infer human plots from long-run traces in the material world – the abstractions of Victorian logic acquire concrete form. In The Mayor of Casterbridge (1886), by contrast, serial iterations are compressed into images. Hardy designs literary equivalents of Francis Galton’s “composite photographs,” used to model statistical data and mental processes. Characters think in overlays, detecting a parent’s face playing over that of a child, designing a future self by laying transparencies over the present, and imagining human plots as grids from overhead. Serial and composite thinking extend to Hardy’s “approximative” theory of fiction. He uses these tropes as an implicit riposte to critics and advocates for a novelistic realism tolerant of repetition, coincidence, and improbability.

I distinguish three versions of the idea of a peculiarly female intelligence, each devised by men to explain and justify their superior social position. First, from Aristotle through to the nineteenth century, the difference was understood in terms of polarities, e.g., female intuition version male reason. Abilities such as abstract thought, considered alien to women, were seen as indispensable for grasping moral principles. Influenced by Darwin’s theory of evolution, Francis Galton replaced the polarities with a single continuous general intelligence (“natural ability”), which be believed was inherited by men and women. This second version granted women and men the same kind of intelligence, although women, on average, were believed to have less of it. In the early twentieth century, Louis Terman put an end to this view by eliminating particular items from the Stanford-Binet test so that the means of male and female intelligence were the same – otherwise, female means would, in fact, have been higher. A third version, promoted by the sexologist Havelock Ellis, again attempted to defend male hegemony by asserting that women have lower variability in physical and mental traits.

The previous themes reach into modern debates about freedom and necessity, which are still central in education and psychology today. Contributing to the rise of formal disciplines of developmental and child psychology, educational psychology, clinical psychology and cognitive psychology, as well as psychiatry, empirical approaches based on sense perception began in the mid-eighteenth century; but they are equally the outcome of broader religious and cultural influences. The book therefore concludes with an overview of the direct traces on the modern disciplines of the religious ideas discussed in earlier chapters: in Britain through David Hartley, Joseph Priestley and Francis Galton, and the nature-versus-nurture formula; and in France Hippolyte Taine, Alfred Binet (creator of the ‘mental age’ score, subsequently IQ measurement) and Jean Piaget himself.