“A spectrometer does not perceive blue. So what then, does it mean to be ‘conscious’ of colour?”
“First coined in 1995 by the Australian philosopher David Chalmers, this ‘hard problem’ of consciousness highlights the distinction between registering and actually feeling a phenomenon. Such feelings are what philosophers refer to as qualia: roughly speaking, the properties by which we classify experiences according to ‘what they are like’.”
“In 2008, the French thinker Michel Bitbol nicely parsed the distinction between feeling and registering by pointing to the difference between the subjective statement ‘I feel hot’, and the objective assertion that ‘The temperature of this room is higher than the boiling point of alcohol’ – a statement that is amenable to test by thermometer.”
“A slew of books over the past two decades have proffered solutions to the ‘problem’ of consciousness. Among the best known are Christof Koch’s The Quest for Consciousness: A Neurobiological Approach (2004); Giulio Tononi and Gerald Edelman’s A Universe of Consciousness: How Matter Becomes Imagination (2000); Antonio Damasio’s The Feeling of What Happens: Body and Emotion in the Making of Consciousness (1999); and the philosopher Daniel Dennett’s bluntly titled Consciousness Explained (1991).”
“For medieval Europeans, subjectivity extended beyond the grave. And that was the point. Self-awareness wasn’t an end in itself, it was a mechanism by which humans with their eternal souls were embedded in a cosmic scheme linking everything to an Ultimate Good. Heaven and Earth were two separate yet intertwined domains of human action. Medieval cosmology was thus inherently dualistic: the physical domain of the body had a parallel in the spiritual domain of the soul; and for medieval thinkers, the latter was the primary domain of the Real.”
“When modern science swept away this dualistic symbolic schema, Europeans came to see themselves as inhabitants of a Euclidean void: we lived on a planet that orbited an insignificant star in potentially infinite space. As described by geometry and physics, this space was understood to be controlled by mathematical laws. And, in this despiritualised, Euclidean space, human figures, including Christ and the saints (now equally subject to natural law) were necessarily depicted at the same scale. The homogeneous, featureless Euclidean void, which forms the backdrop to Galilean and Newtonian science, has its visual correlate in the homogeneous scheme of perspectival representation that unified earthly and heavenly space. Now all objects were placed within a single frame of reference.”
“Perspective, delightfully known in the 13th century as ‘geometric figuring’, enabled artists to simulate the illusion of physical depth, but it removed the metric by which they had previously represented moral depth. Just as art became literal rather than iconic with the advent of modern science, our concept of a moral universe became subject to homogenisation, and finally to a kind of erasure.”
“If the condition of the world is mathematical, and the space of reality is geometric, then can’t we dispense with the spiritual stuff and just get on with the business of plotting our co‑ordinates in Euclidean space, refining in ever more detail the ‘laws’ that operate within it? Thus was born materialism, which viewed humans as purely physical objects made up of component parts moving in space according to mathematical laws. De-souled, stripped of a cosmic connection to God, humans became sub-units of the world-machine.”
“Although full-blown materialism (an early variant of physicalism), wasn’t articulated until the 18th century, its shadow was already hovering in Galileo’s 17th-century distinction between objective and subjective qualities. In his book The Assayer (1623), Galileo wrote: ‘If ears, tongues, and noses were removed, I am of the opinion that shape, quantity and motion would remain, but there would be an end of smells, tastes, and sounds.’ Shape, quantity and motion – these were not only the objects of science, they were the primary reality.”
“Here was presaged a future that Descartes had struggled to avoid. For while Descartes championed mathematical science as a way forward for understanding the physical world, as a Catholic, he also insisted on the reality of the Christian soul. Hence his famous dualism, with its two domains of being: the res extensa (the extended realm of matter in motion), and the res cogitans (the realm of thoughts, feelings, emotions and moral action). Descartes wanted to preserve the essence of medieval dualism while simultaneously opening up a space for mathematical science. This was his special genius; he invented co-ordinate geometry (enabling us to better navigate inert Euclidean space), yet at the same time he attempted to ‘save’ the phenomenon of the soul.”
“Heaven and hell aren’t only Christian places: they are also states of mind. Whatever our bodies are doing in physical space, we also inhabit psychic space and we need ways to talk about the states that minds are in.”
“Henry James, Marcel Proust and Franz Kafka propel us into the unique sensibilities of their protagonists. James, whose writing has been likened to a literary version of impressionism, was deeply interested in representing the consciousness of his characters, while his brother, the psychologist and philosopher William James, gave us the term ‘stream of consciousness’ to describe the flow of thoughts, feelings and ideas that ramble through our minds. James coined this term in his book The Principles of Psychology (1890), and in the early decades of the 20th century it came to be associated with such quintessentially modernist writers as James Joyce.”
“But perhaps most surprisingly, just when the ‘stream of consciousness’ was entering our lexicon, physicists began to realise that consciousness might after all be critical to their own descriptions of the world. With the advent of quantum mechanics they found that, in order to make sense of what their theories were saying about the subatomic world, they had to posit that the scientist-observer was actively involved in constructing reality. At the subatomic level, reality appeared to be a subjective flow in which objects sometimes behave like particles and other times like waves. Which facet is manifest depends on how the human observer is looking at the situation.”
“Forty years ago, the American theoretical physicist John Wheeler proposed a series of thought experiments to test if an observer could affect whether light behaved as a particle or a wave and, in 2007, the French physicist Alain Aspect proved that they could. Just this April, Nature Physics reported on a set of experiments showing a similar effect using helium atoms. Andrew Truscott, the Australian scientist who spearheaded the helium work, noted in Physics Today that ‘99.999 per cent of physicists would say that the measurement… brings the observable into reality’. In other words, human subjectivity is drawing forth the world.”
“Pain is surely like this too: it must have neurological correlates otherwise we wouldn’t be able to react to withdraw a hand from a flame and save our bodies from damage. (People who lose the ability to feel pain quickly succumb to injuries.) At the same time, pain transcends its physical dimensions, as do the many species of misery catalogued in Dante’s Hell, and represented to us in daily news accounts of the effects of war on millions of people today.”
“Giulio Tononi’s book Phi (2012) asks the question: ‘How could mere matter generate mind?’ As a neuroscientist, Tononi says this is a mystery ‘stranger than immaculate conception… an impossibility that defie[s] belief’. Nonetheless, he offers us an explanation of consciousness grounded in information theory that has been admired by both Tegmark and Koch. He wants to do for psychic phenomena what Descartes, Galileo and their heirs did for physical phenomena: he wants to explain subjective experience by generalised empirical rules, and he tells us that such experiences have shapes in a multidimensional mathematical space.”