In a recent paper, ‘Naturalism without metaphysics’, philosopher John Collins notes that scientific naturalism does not have to be a metaphysical position, and in fact any serious naturalist must suppose that their metaphysics reaches only as far as their theoretical constructs. This methodological naturalism is therefore ‘an antimetaphysical doctrine’. Science proceeds on whatever course it takes, neither feigning (metaphysical) hypotheses nor establishing arbitrary ontological divisions like mind vs body. There is, in the end, only the world, with its various properties, defined by natural science as ‘optical’, ‘chemical’, ‘cosmological’, and so forth.
Indirectly supporting this naturalistic stance, Edmund Burke, like Oscar Wilde (for whom ‘to define is to limit’), proposed in his modestly entitled A Philosophy Enquiry into the Origin of our Ideas of the Sublime and Beautiful in 1757: ‘When we define we seem in danger of circumscribing nature within the bounds of our own notions, which we often … form out of a limited and partial consideration of the object before us, instead of extending our ideas to take in all that nature comprehends, according to her manner of combining. … A definition may be very exact, and yet go very little way towards informing us to the nature of the thing defined.’
The deep Chomsky develops this further: ‘Science talks about very simple things, and asks hard questions about them. As soon as things become too complex, science can’t deal with them. The reason why physics can achieve such depth is that it restricts itself to extremely simple things, abstracted from the complexity of the world. As soon as an atom gets too complicated, maybe helium, they hand it over to chemists. When problems become too complicated for chemists, they hand it over to biologists. Biologists often hand it over to the sociologists, and they hand it over to the historians, and so on. But it’s a complicated matter: Science studies what’s at the edge of understanding, and what’s at the edge of understanding is usually fairly simple. And it rarely reaches human affairs. Human affairs are way too complicated.’
Joseph Priestley, one of the most influential chemists of his age, thought the Cartesian theory that reasons that a man is ‘capable of thinking better when the body and brain are destroyed, seems to be the most unphilosophical and absurd of all conclusions.’ Keats, Shelley and Coleridge, along with other Romantic poets, were heavily influenced by this naturalistic account of the mind. Priestley later came to the accurate conclusion that ‘the powers of sensation or perception and thought, as belonging to man, have never been found but in conjunction with a certain organized system of matter; and therefore, that those powers necessarily exist in, and depend upon, such a system. This, as least, much be our conclusion, till it can be shown that these powers are incompatible with other known properties of the same substance; and for this I see no sort of pretence … we ought to conclude that the whole man is material unless it should appear that he has some powers or properties that are absolutely incompatible with matter.’
Hilary Putnam adds: ‘Science as we know it has been anti-metaphysical from the seventeenth century on: and not just because of ‘positivistic interpretations’. Newton was certainly no positivist; but he strongly rejected the idea that his theory of universal gravitation could or should be read as a description of metaphysically ultimate fact. (‘Hypotheses non fingo’ was a rejection of metaphysical ‘hypotheses’, not of scientific ones.).’ ‘Matter’ and ‘physical’ are simply terms which stand for whatever entities are postulated by present naturalism, with any Cartesian intuitions about mechanical causes failing to explain the possible existence of Majorana particles, which are simultaneously matter and anti-matter (even the fact that matter is mostly empty space does not deny its place amongst ‘the physical’: ‘Anti-matter’ is still ‘matter’, so to speak.).
It is important to stress, then, that ongoing science has no worldview at all, no hypotheses, just methodologies and posited entities existing within particular explanatory theories. Edward Witten agrees: ‘It’s good to bear in mind that in the nineteenth century physicists didn’t even have the aspiration to explain why glass is transparent or why grass is green, why ice melts at the temperature it does, and so on. The progress of physics has always been such that the level of understanding for which one generation aims wasn’t even dreamed of a generation or two earlier.’
Putnam also once pointed out that ‘even the simple fact that a square peg won’t fit into a round hole cannot be explained in terms of molecules and atoms but only at a higher level of analysis involving rigidity (regardless of what makes the peg rigid) and geometry.’ In addition to Chomsky’s point, Gell-Mann has said that reduction in the natural sciences as a method of unification is ‘great, but it will only take you so far in the study of complex subjects. Do you try to understand earthquakes in terms of quarks? Of course not. You use intermediate concepts, like plate tectonics and friction.’
Upon meeting his friend and student, Elizabeth Anscombe, in a corridor at Cambridge, Wittgenstein asked her: ‘Tell me, why do people always say it was natural for man to assume that the sun went round the Earth rather than that the Earth was rotating?’ Anscombe replied: ‘Well, obviously because it just looks as though the sun is going round the Earth.’ Wittgenstein responded: ‘Well, what would it have looked like if it had looked as though the Earth was rotating?’ If Anscombe found herself unable to reply, she had only her constrained and adapted wits to blame. Science is unavoidably directed by natural biases and proclivities, often with the boundary between scientific construct and conceptual paradox not being at all clear.
Consider the notion of time, which has largely proved itself to be an intractable problem. Common sense conceptions of time haven’t changed since Augustine wrote the Confessions: ‘It is not strictly correct to say that there are three times, past, present and future. It might be correct to say that there are three times, a present of things past, a present of present things, and a present of future things.’ When asked what his experience of time was like during a mescaline trip, Aldous Huxley replied in The Doors of Perception: ‘There seems to be plenty of it.’ String theorist Brian Greene, on other hand, might not agree with him: ‘Time is with us, every moment. I can’t even say a sentence without invoking a temporal word – moment. But what is time? When we look at the mathematics of what it is or where it came from, time is there, but there’s no deep explanation of what it is or where it came from.’
Adding to this, physicist Sean Carroll believes ‘We have no right to claim that the universe and time started at the big bang, or had some sort of prehistory.’ After the collapse of Cartesian mechanical philosophy, Leibniz, rivaling Newton, proposed that change is the fundamental property of the universe, while time emerges from our mental efforts to organise the changing world around us. Carlo Rovelli, a physicist at the Centre for Theoretical Physics in Marseilles, has ‘rewritten the rules of quantum mechanics so that they make no reference to time.’ Echoing Leibniz, he claims that ‘Physics is not about “how does the moon move through the sky?” but rather “how does the moon move in the sky with respect to the sun?” Time is in our mind, not in the basic physical reality.’ For Dean Rickles, a philosopher of science at the University of Sydney, neither quantum physics nor general relativity can account for the existence of time: ‘It is highly likely that what we think of as time emerges from some deeper, more primitive non-temporal structure.’
Linda Geddes adds that, ‘While we have a fairly good grasp on the millisecond timing involved in fine motor tasks and the circadian rhythms of the 24-hour cycle, how we consciously perceive the passage of seconds and minutes – so-called internal timing – remains decidedly murky.’ For humans ‘there is no dedicated sensory organ for time perception, as there are for perceiving the physical and chemical nature of our environment through touch, taste and smell. Time is also unusual in that there is no clinical condition that can be defined purely as a lack of time perception, which makes it difficult to study.’ Time is ‘so fundamental to cognition that our brains have developed several back-up systems that can kick in if the main clock is damaged, which is why it is so difficult to find anyone who cannot perceive time.’
René Magritte, an artist with an eye for the illusory, held that ‘We see [the world] as being outside ourselves, although it is only a mental representation of what we experience inside ourselves. … Time and space thus lose that unrefined meaning which is the only one everyday experience takes into account.’ But notions like time and consciousness, while attractive and intriguing, often derail serious inquiry into more empirically manageable topics. As Montaigne wrote, ‘I have always felt grateful to that girl from Miletus who, seeing the local philosopher … with his eyes staring upwards, constantly occupied in contemplating the vault of heaven, made him trip over, to warn him that there was time enough to occupy his thoughts with things above the clouds when he had accounted for everything lying before his feet.’
Relatedly, Kurt Lewin’s notion of Galilean explanations, as opposed to Aristotelian ones, is a distinction in the physical sciences which Cedric Boeckx has recently carried over to the cognitive sciences: ‘Aristotelian laws or explanation have the following characteristics: they are recurrent, that is statistically significant; they specifically (though not always) target functions, that is they have a functionalist flavor to them; they also allow for exceptions, organized exceptions or not, but at least they allow for exceptions; and finally they have to do with observables of various kinds. … [Galilean laws] are typically formal in character, and they are very abstract mathematically. They allow for no exceptions and they are hidden. That is, if you fail to find overtly the manifestation of a particular law that you happen to study, this does not mean that it is not universal. It just means that it is hidden and that we have to look at it more closely and we will eventually see that the law actually applies.’
Ernst Mayr, in his deeply-informed study What Makes Biology Unique?, wrote that in the study of the organic world ‘to have isolated all parts, even the smallest ones, is not enough for a complete explanation of most systems,’ noting further that ‘laws certainly play a rather small role in theory construction in biology’ ‘because evolutionary regularities do not deal with the basics of matter as do the laws of physics. They are invariably restricted in space and time, and they usually have numerous exceptions.’
At this point it is useful to distinguish between intuitive explanations (a form of folk science) and scientific ones. The former is reminiscent of Kepler’s astronomical theory in 1619 work The Harmonies of the World, which ‘affirmed that the planet’s elliptical orbits caused each to produce a series of rising and falling notes, radically unlike the supposed monotonous droning of the Ptolomaic spheres; together, the planets sang in a polyphony that could be heard only by the Composer.’ This added to the beliefs of other pre-Newtonian astronomers, who thought the planets of the solar system had senses. This is similar to Schopenhauer’s view of astronomy, ‘where heavenly bodies sport with each other, betray inclination, and as it were exchange amorous glances, though never driving matters so far as coarse contact, but, keeping due distance, decorously dance their minuet to the music of the spheres.’
Contrary to Quine’s view that an understanding of substances and individuals depends on an acquired quantificational syntax (such as the mass-count distinction), Soja, Carey and Spelke have shown that during the earliest stages of language acquisition, children make use of conceptual categories of ‘substance’ and ‘individual’ virtually equivalent to those used by adults, forming our ‘intuitive materials-science.’ Count nouns are unbounded and made of individuals, whereas the opposite applies to mass nouns, leading Pinker to suggest that ‘our basic ideas about matter are not the concepts “mass” and “mass” but the mini-concepts “bounded” and “made up of individuals.”’ Unlike pebbles and gravel, collective nouns like ‘committee’ are both bounded and made of individuals: but again, these are not metaphysical matters. ‘Hair’ and ‘hairs’ are respectively count and mass nouns, but a physicist would not ask with Richard Lederer ‘why a man with hair on his head has more hair than a man with hairs on his head.’
Correspondingly, ontological questions about what things ‘really are’ are left aside as a hindrance, of no more concern to cognitive science than the classical categories of ‘earth’, ‘air’, ‘fire’ and ‘water’ are to physics. We are in a similar position as the medieval scholastics, with ‘the world’ once again beyond comprehension, a feeling Plato touched on when musing on the accumulation of knowledge: ‘Every one of us is like a man who sees things in a dream and thinks that he knows them perfectly and then wakes up, as it were, to find that he knows nothing.’
As has happened in the past, it is quite possible that we are miscategorising the problems of science when we talk about time and other matters. I will call this the Problem of Naturalism, which has two complementary levels:
The Problem of Naturalism: (i) How much of physical theory can be reduced to human conceptual structure? (ii) How much of our conceptual capacities can be accounted for in physical terms?
Possible candidates for the first question are space and time, while candidates for the second question include particular (and possibly optimal) computations of the human language faculty. For instance, the operation of Concatenation simply takes two conceptual units/representations and constructs an unordered set out of them, e.g. [α, β]. Sidelining a lot of important details, we can briefly summarise that the sensorimotor system that language interfaces with naturally imposes some form of order on the externalised representations (that is, words have to be spoken in a particular order, not instantaneously). This parsing and externalisation constraint, however, doesn’t seem to apply to the conceptual interface, which recognises only hierarchical relations between words.
Returning to the above naturalistic concerns, the Problem of Naturalism is one of the reasons why Carnap and Quine’s advocation of reducing philosophy to science through introducing the ‘philosophy of science’ has been entirely misleading and damaging, since it presupposes two separate methodologies and areas of inquiry: the ‘scientific method’ and, even more obscurely, the ‘philosophical method’. Many philosophers like Quine, Carnap, Toulmin and Popper first took degrees in physics or mathematics, only later turning to philosophical questions, their love of a priori reflection presumably intact. Terms like ‘philosophy’, ‘science’, ‘matter’ and ‘mind’ are largely historical residues, and considering them in isolation by ignoring their origins only leads to confusion.
There are, of course, different kinds of theories within the sciences, some stressing the importance of natural selection (evolutionary psychology), others physical constraints (theoretical biology), others ‘elegance’ and ‘beauty’ (theoretical physics, cosmology, minimalist syntax), but none of them cohere mysteriously by following the same ‘method’ any more than artists follow the same ‘aesthetic method’ when painting portraits or crafting sculptures. As Otto Neurath explained, ‘There is no scientific method. There are only scientific methods. And each of these is fragile; replaceable, indeed destined for replacement; contested from decade to decade, from discipline to discipline, even from lab to lab.’
More generally, as Galen Strawson notes, ‘In cognition we never do more than aim or tilt our minds; the rest is up to nature, trained or not. Much bodily movement is ballistic, relative to the initiating impulse; the same goes for thought.’ We cannot we rid ourselves of the capacity for imagination and thought that the evolution of language (likely) yielded. They are, as Heinrich von Kleist understood in his short story ‘On the Marionette Theatre’, species-defining properties: ‘“Grace appears purest in that human form which has either no consciousness or an infinite one, that is, in a puppet or in a god.” “Therefore,” I said, somewhat bewildered, “we would have to eat again from the Tree of Knowledge in order to return to the state of innocence?” “Quite right,” he answered. “And that’s the last chapter in the history of the world.”’