Is everything conscious?

If the question makes no sense to you, try spending some time with the principle of sufficient reason

by Sam Kimpton-Nye  BIO

Photo by Bjoern Steinz/Panos Pictures

is a lecturer in philosophy at the University of Southampton, UK. He is the co-author, with Toby Friend, of Dispositions and Powers (2023).

When an explanation makes a fact intelligible, the mystery goes out of it. We understand it so well that we can hardly conceive of things being otherwise. Consider the simple mathematical fact that one plus one equals two. Once we understand elementary arithmetic, we no longer feel the urge to ask why one plus one equals two. That one plus one equals two strikes us as not merely true but unavoidable; we cannot even coherently imagine its falsity. Much of philosophy aims to bring other fundamental features of reality into a similar light, to make them appear not arbitrary but inevitable and, thus, intelligible.

This aspiration that philosophy render the world intelligible is best expressed by the German polymath Gottfried Wilhelm Leibniz and the Dutch philosopher Baruch Spinoza. According to Leibniz: ‘we can find no true or existent fact … without there being a sufficient reason why it is thus and not otherwise.’ And, as Spinoza wrote: ‘For each thing there must be assigned a cause or reason, both for its existence and for its nonexistence.’ What’s being expressed here, in the words of the US philosopher Michael Della Rocca, is the desire ‘to make the world and our place in it intelligible’. To grasp the kinds of reasons or explanations sought by Leibniz and Spinoza ‘is the perennial hope and promise of philosophy’.

The demand for intelligibility can lead to some extraordinary places. For Leibniz, the demand led him to propose that reality is ultimately made up of a multiplicity of monads: indivisible, infinitesimally small units of substance, each of which is a causally isolated, self-contained universe. Spinoza’s resolute commitment to universal intelligibility led him to conclude that reality is, instead, a single infinite substance that he called God or nature. As we will see, the demand for intelligibility can also lead into the strange and fascinating world of panpsychism.

Panpsychism is an increasingly popular view about consciousness. You are conscious, you feel pleasures, pains and all manner of other experiences. At every waking moment, and even when you dream, there is something that it is like to be you. The same goes for other humans and animals, and this accounts for moral status: thumping a fist on a desk in frustration is morally permissible in a way that hitting a conscious person or animal is not. Desks, chairs, rocks and so on are not conscious – and are therefore without moral status – whereas humans, bonobos, dogs and so on are conscious, and deserving of at least some moral recognition. But panpsychism rejects this division into conscious and non-conscious things. It is the view that consciousness is a fundamental property of matter, so everything from electrons and protons to tables and planets, and, of course, humans and dogs, has consciousness to some degree.

Panpsychism is a remarkable thesis, motivated by the ‘perennial hope’ that the world is ultimately intelligible. To investigate whether panpsychism truly can make the world intelligible, we will explore three different arguments, each of which is grounded in a principle that crystallises the ambitious aim of universal intelligibility: the principle of sufficient reason (PSR). This simple and plausible principle of philosophical enquiry – that there exist satisfying explanations for everything – can lead to a whole new understanding of the nature of reality. And, though I’m sceptical about the availability or even desirability of explanations that dissolve all the world’s mysteries, there is exceptional value in the mere contemplation of such projects.

If you come home from work to find a bouquet of flowers on your doorstep, there will be a reason for this. Maybe it’s a birthday present, a congratulations on a new job, a thank you for some good deed. If your car dashboard shows a warning light, you’d be wise to assume that there is some reason for this, such as a problem with the engine, fluids or tyres. The Chicxulub crater, 200 km wide and 1 km deep, in the Yucatán peninsula in Mexico, cries out for scientific explanation, which is precisely what the hypothesis of an extinction-level asteroid impact millions of years ago provides.

But is there really a reason for everything? The mass of a proton is 1.672 × 10-27 kg. What’s the reason for this? What’s the reason for a particular radioactive decay event to which our best scientific theory on the issue, quantum mechanics, assigns only a probability? According to the PSR, there is indeed a reason for everything. For any way the world is, from the flowers on your doorstep to the mass of a proton, there is some reason why it is this way and not some other way. All facts have a reason, and – according to the PSR in its strongest form, as defended by Spinoza – that reason makes them intelligible and necessary, and their contrary inconceivable.

Though the PSR found its fullest expression in Leibniz’s work – ‘The fundamental principle of reasoning,’ Leibniz wrote, ‘is that there is nothing without a reason’ – its lineage is far greater. As Della Rocca showed in his book Spinoza (2008): ‘Versions of [the PSR] go way back in philosophy and can be found in philosophers such as Parmenides, the Stoics, [and] Aquinas.’ And the principle is not restricted to Western European philosophy. It occupies a key position in the metaphysical system of the Islamic philosopher Ibn Sīnā (also known in Europe as Avicenna), who used it to argue that things that exist merely contingently – that is, things whose existence is not necessary – must have a cause outside themselves. Versions of the principle have also been defended in contemporary metaphysics and philosophy of physics. Shamik Dasgupta has argued that every substantive fact has a metaphysical grounding that makes it necessary. And Eddy Keming Chen has developed a physical model of the Universe according to which every single fact (from the number of hairs on your head at 2 pm this afternoon, to the mass of the electron) is entailed and thus explained by the laws of nature.

The PSR is so alluring because it would seem that the very activity of enquiry – whether philosophical, scientific, or the first ‘Why?’ question of a young child – is premised on there being an explanation, a reason, for everything. To endorse the PSR is to adopt an attitude of optimism that the world and our place in it are intelligible and infused with reason and meaning. If anything were unexplainable, there’d be a grave risk that human enquiry is ultimately futile. The falsity of the PSR would constitute a fundamental mismatch between our inquisitive nature and the world in which we find ourselves; it would imply that the world is unintelligible.

The optimistic attachment to intelligibility and reason comes at a significant cost

Intelligibility and meaningfulness are two sides of the same coin. When, on reflection, we can find no good reason for our personal and professional pursuits (lining the boss’s pockets won’t generally satisfy us!), when these things seem absurd or unintelligible, it’s natural to express the predicament in terms of a lack of meaning in life. Analogously, failure........

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