‘Magnificent Intellect’: Character, Intelligence, and Genius in Sherlock Holmes

Since his first appearances in print, Sherlock Holmes has served as literature’s resident genius. But what does ‘genius’ mean in a world that increasingly conceptualises intelligence as a quantifiable and measurable phenomenon? This essay considers the characterisation of Holmes’s intelligence in the context of a revolution in the way human intelligence is understood – a revolution instigated by Francis Galton’s 1869 Hereditary Genius and emblematised by the invention of the IQ test in 1905. This historical context situates Holmes’s character at the crux of a shift in the conception of intelligence, as encapsulating a moment of cultural wavering between ‘genius’ as a mysterious quality or gift, and ‘genius’ as a higher-than-average number on a scale. Ultimately, this essay suggests that these competing models of the characterisation of intelligence in the Holmes stories illuminate a fundamental clash between the novelistic ideal of portraying incommensurable individuality on the one hand, and the de-individualising trend of the IQ model of intelligence on the other.