Nyāya Substance Dualism

In a previous post, I went over an argument for the existence of God that was formulated by philosophers in the Nyāya tradition. Here my aim is to provide a brief summary of some Nyāya arguments for substance dualism, the view that mental and physical substances are radically distinct.

The categories of substance and quality were fundamental to Nyāya metaphysics. A substance is the concrete substratum in which qualities inhere. An apple, for instance, is a substance, and redness is a quality that inheres in it. Substances can be complex and made up of parts (like an apple) or simple and indivisible (like an atom).

Nyāya held that in addition to physical substances, there are non-physical ones. Our individual soul – that is, our Self – is a non-physical substance. Like atoms, individual souls are simple and indivisible, and hence eternal (since destroying an object is the same as breaking it up into its constituent parts, and simple substances do not have any constituent parts). Consciousness, and different conscious states like desires and memories, are qualities that inhere in the substantial Self.

The primary philosophical adversaries of Nyāya belonged to two different camps. The first was Cārvāka, which claimed that only physical substances exist, that the mind does not exist apart from the body, and that the self is reducible to the totality of the body and all its functions. The other was Buddhism, which rejects physicalism but denies the existence of the substantial Self. Buddhism replaces the idea of the Self with a stream of momentary causally connected mental states. Nyāya was engaged in a protracted series of debates with both Cārvāka and Buddhism. Versions of the arguments I summarize in this essay were developed and defended by Nyāya thinkers such as Vātsyāyana (5th century), Uddyotakara (7th century) and Udayana (10th century), among others.

Against Physicalism 

Nyāya came up with a number of arguments against physicalism. The one I focus on here has interesting similarities to arguments found in contemporary debates within the philosophy of mind. It can be stated like this1:

(P1) All bodily qualities are either externally perceptible or imperceptible.

(P2) No phenomenal qualities are externally perceptible or imperceptible.

(C) Therefore, no phenomenal qualities are bodily qualities.

The argument is deductively valid, so let us examine the premises. As the term suggests, externally perceptible bodily qualities are features of the body that can be directly perceived by external agents. Color is an example of an externally perceptible quality. Everyone who can see me can see that the color of my body is brown. An imperceptible quality is a feature of the body that cannot be directly perceived, but can be inferred through observation and analysis. Weight was a common example used in Nyāya texts. You cannot directly perceive my weight, but if I stand on a weighing machine, you can know my weight by looking at the number displayed by the machine. P1 states that all physical qualities are exhausted by these two categories.

Let us movie on to P2. Phenomenal qualities are the features of conscious experience: the subjective, first person what-it-is-likeness to have an experience. The experience of color, pleasure, pain, desire, and memory are all examples of phenomenal qualities. P2 draws on the intuition that phenomenal qualities are essentially private.

To say that phenomenal qualities are not externally perceptible is to say that I cannot immediately know what it is like for you to have an experience. I have direct access to externally perceptible qualities of your body like color, but I don’t have direct access to your phenomenal qualities. I may be able to infer based on your behavior that you are in pain, but I don’t experience your pain in the immediate, first person manner that you do. The contemporary American philosopher Thomas Nagel made a similar point in his classic paper What Is it Like to Be a Bat? We may be able to observe how bats behave, and how their organs, brain and nervous system work, but we can’t know what it feels like, from the inside, to be a bat. Only a bat knows what it is like to be a bat.

If phenomenal qualities aren’t externally perceptible, perhaps they are imperceptible qualities like weight. But this is extremely implausible. Phenomenal qualities are not externally perceptible, but they’re clearly internally perceptible. The whole point is that I have direct perceptive access to phenomenal qualities – my conscious experiences are given to me in a basic and immediate fashion. Even if I don’t know that my experiences are veridical, I always know what the features of my own experience are. Thus, phenomenal qualities are not imperceptible.

Since phenomenal qualities are neither externally perceptible nor imperceptible, they are not physical qualities. If physicalism is the thesis that only physical substances and their qualities exist, and the above argument is sound, we must conclude that physicalism is false.

Against No-Self Theory 

The above argument by itself does not get us to the kind of substance dualism that Nyāya favored. Buddhists, after all, are anti-physicalists, but they do not believe that the Self is an enduring substance that persists through time. Instead, Buddhists view a person as nothing more than a series of sequential causally connected momentary mental states. The 18th century Scottish philosopher David Hume, and more recently, the British philosopher Derek Parfit, came to roughly the same conclusion.

Again, the Nyāya canon has several arguments against the Buddhist no-Self theory, but I will touch on just two of them here. The first of these is that the Self is necessary to explain the first person experience of recollection or recognition. The intuition here is something like this: If I notice a tree and recognize that it is the same tree I saw a few days ago, there has to be a subject that was present both during the first experience and the second one for recollection to occur. Similarly, if the desire to eat a banana arises in my mind at t2 because I remember that I previously enjoyed eating a banana at t1, there has to be a subject that existed during the initial experience that occurred at t1, and persisted through time until the recollection at t2. Without the Self – a substance that endures through these different points in time – the experience of memory is a mystery.

The Buddhist response was that causal connections between momentary mental states could explain the phenomenon of memory. If the mental state at t1 is causally connected to the mental state at t2, that’s all that’s needed for the mental state at t2 to recall the experience at t1. The Nyāya rejoinder was that causal connections were not sufficient to account for how a mental event can be experienced as a memory. When I recognize a tree I saw few days ago, it isn’t just that an image of the previously perceived tree pops into my mind. Rather, my experience is of the form: “This tree that I see now is the same tree I saw yesterday.” In other words, my present experience after seeing the tree involves my recognition of the previous experience as belonging to myself. Similarly, my current desire to eat a banana is based on my recognition of the previous enjoyable experience of eating a banana as belonging to myself. One person does not experience the memory of another, and in much the same way, one mental state cannot remember the content of another. So a single entity that persists through time must exist.

The second argument for the Self takes for granted what we might call the unity of perception. Our perceptions aren’t a chaotic disjointed bundle despite the fact that they arise through different sense organs. There’s a certain unity and coherence to them. In particular, Nyāya philosophers drew attention to mental events that are characterized by cross-modal recognition. An example would be: “The table that I see now is the same table I am touching.” We have experiences that arise through different channels (in this case, my eye and my hand), but there must be something that ties these experiences together and synthesizes them to give rise to a unified cognitive event. In other words, the Buddhist no-Self theory might be able to explain the independent experiences of sight and touch, but for the object of both experiences to be recognized as one and the same, there must something else to which both experiences belong, and which integrates the experiences to give rise to the unified perception of the object. Again, it seems we must admit the existence of the Self.

Needless to say, all these arguments were (and remain) controversial. The debates between Buddhist and Nyāya philosophers got extremely complex over time. They involved increasingly fine-grained analyses of the phenomenology of recollection/recognition, and increasingly technical discussions on the metaphysics of causation. Similar debates took place between other orthodox Indian schools of thought that believed in the Self (Mīmāṃsā, Vedānta, etc.) and their Buddhist no-Self rivals. A good place to start for further reading on this subject would be the collection of essays in Hindu and Buddhist Ideas in Dialogue: Self and No-Self. 

Notes

[1] The argument I’ve presented here is based on Kisor Kumar Chakrabarti’s formulation in Classical Indian Philosophy of Mind: The Nyāya Dualist Tradition. 

How to Interpret Plato

Interpreting Plato is difficult work. It is made even more difficult with the strategy championed by Gregory Vlastos and commonly employed by Analytic philosophers. This strategy has three main commitments: (1) Plato’s views are distinguished from those of Socrates, (2) both views are constructed on the basis of the arguments presented in Plato’s dialogues, and (3) those arguments are interpreted with an eye to constructing a cohesive view for both philosophers. All three of these strategic commitments are problematic and hold us back from rightly understanding Plato’s corpus.[i] And all three commitments are derived from the same basic oversight: Plato wrote dialogues to be read.[ii]

Plato begot the tradition of Socratic dialogues as a medium for public debate. Artistic works such as tragedy and comedy were an important element of Athenian democracy. Poets were divinely inspired: the moral dilemmas presented in their works were given by the gods, and their lessons were taken seriously by the demos as a result. But by the end of the fifth century, Athens was declining. Devastating civil wars ravaged the city amid the Spartan victory in the Peloponnesian War and the subsequent dissolution of the Delian League, which provided Athens its wealth and its power.  The demos was hungry for change, and Plato, among others, was willing to bring it. He positioned philosophy as an alternative to tragedy and comedy. This is well known. But he also positioned it as continuous with these more dominant genres. It is this continuity that often goes ignored and is really at issue when we consider (1), (2), and (3). Let us turn to these commitments themselves, beginning with (1).

Plato is often denigrated as something of a scribe, someone who merely recorded the conversations of Socrates for posterity. This is what other Socratic dialogue writers purport to do. Xenophon, for instance, explicitly claims to present the conversations of Socrates as they really took place, according to what he and his sources could remember. But Xenophon criticises Plato for putting words in Socrates’ mouth that he did not say.[iii] This should be historically unsurprising since there was at least a decade between Socrates’ death and the publication of Plato’s first dialogue. Surely Plato would have forgotten the precise wording of Socrates’ conversations. But so too would have Xenophon. What seems more likely is that Xenophon’s critique is not merely pedantic but principled. He knows that Socrates didn’t say what Plato wrote because Socrates couldn’t have said those things. Socrates’ opinion differed from what Plato presented in a way that would have been well known to Socrates’ followers. So what, then, is going on? The answer is pretty simple given the history of Athenian poetry more generally. Socrates was a caricature in Plato’s dialogues just as he was in Aristophanes’ Clouds. Everyone knew who he was and some general features of his personality and his life. But more importantly, Socrates was well known to have been sentenced to death in 399, and by the time of Plato’s writing, this was a matter of severe public guilt. Plato was no doubt inspired by his teacher, but he also capitalised on the facts surrounding his life and his death for his own ends. And hence the picture that Plato gives of Socrates may not be a faithful one. It need only be close enough for his audience to recognise the character as Socrates the wandering questioner. So how then can we on the basis of Plato’s dialogues distinguish between Plato’s view and Socrates’? Quite obviously, we cannot.

The method that Vlastos and others appeal to to make that distinction is to evaluate the arguments presented in the dialogue and all of their various entailments. This method generates two significant questions, one of which we shall leave until we discuss (3). Nowhere does Plato come out and say “I, Plato, will argue for such and such in the following way.” It is left up to the audience to interpret what Plato means by presenting any given dialogue in the way that he has, and in many cases, it is precisely what is not said and not argued that is important for understanding a given dialogue. Perhaps the best example of this is the Meno. The dialogue begins with Meno asking Socrates “Can you tell me, Socrates, can virtue be taught? Or is it not teachable but the result of practice, or is it neither of these, but men possess it by nature or in some other way?” Here we have four possible sources of virtue: teaching, practice, nature, or something else. In the succeeding discussion, Socrates and Meno consider three possibilities: teaching, nature, and the gods. They end up with a hesitant commitment to the gods as the source of virtue. Yet throughout there are allusions to tasks commonly learned by practice, and its absence among consideration is conspicuous, especially given the orthodoxy of the period. This of course does not mean that Plato believed that practice is the source of virtue. It means only that Plato is clear on the inadequacy of the discussion and is pointing it out to his audience. Focusing only on the arguments of the Meno, however, would miss this possibility entirely. It would lead one to believe that Plato truly did believe that knowledge is recollection and that virtue is given by the gods. That may be the case, but it is far from certain, and Vlastos’s method doesn’t clear up the matter.

One way that Vlastos tries to clear up various ambiguities in Plato’s arguments is by committing himself to demonstrating that a given argument is consistent with other arguments elsewhere. He constructs Socrates’ and Plato’s positions as coherent wholes that manifest themselves in the arguments of Plato’s dialogues. Each dialogue then gives a piece of the overall whole that Plato’s audience must then hold together to understand what Plato seeks to show them. The difficulty of doing so should be sufficient to demonstrate the ridiculousness of this commitment. Holding all of Plato’s works in one’s head is difficult enough for specialists, let alone for Plato’s Athenian audience reading a dialogue before all of them had even been written. There of course may be some relationship between some dialogues. There was some speculation by Hellenistic commentators, for instance, that Plato presented his dialogues as tetrologies like the tragedians did.[iv] But aside from that, no one of Plato’s audience would be expected to understand how the dialogue he is reading fits into Plato’s broader view. This might be expected of Plato’s students, but the dialogues were published beyond the academy, and purposely so. As Steven Robinson points out, if Plato was simply writing for his students, he would have no reason to do so.[v] These students are philosophers themselves, and they know better that philosophy is no threat to the polis. What matters, on the other hand, is the opinion of the demos, and it is that which Plato seeks to change. And he can’t do that if the demos must first read and comment on everything that Plato has written and will write. (3) completely misses the point of Plato’s writing. Maybe we can find something common amongst Plato’s corpus as a whole, but this would be no help at all in understanding the point of any single dialogue. The really important interpretative work demands that we understand the individual dialogues, not Plato personally. And to this end, there is no reason why there can’t be ten Platos or ten Socrateses in ten different dialogues.

So how do we interpret Plato? Ultimately, I don’t know. But I do know that we can’t do it like we tend to do now. We have to treat Plato’s dialogues as dialogues. They are not essays in analytic philosophy: we cannot mine them for their arguments and be sated by that alone. We have to consider the traditions that influenced Plato. We have to understand his audience. We have to weigh what has been said against what has not. We have to admit the possibility of irony and satire and other dramatic tropes. All this is what makes Plato so difficult, but also so engaging and persistently rewarding.

Endnotes

[i] This is important for more than merely historical interest. I shall save a full demonstration of this for another time. Briefly, however, when we ask about how to rightly do philosophy, what philosophical methods are appropriate or otherwise, we must defer to what philosophy itself is for. This kind of functional demand can only be decided by looking to the foundations of philosophy and to the problems that it was established to solve. Plato happens to be the centrepiece of those foundations.

[ii] There is some dispute about whether Plato’s dialogues were performed. There is good reason to believe that they were, at least in some respect, but they need not have been in order to support the general appeal to the public upon which my account relies.

[iii] This criticism is specifically about the Lysis, an early dialogue of peripheral import.

[iv] Diogenes Laertius considers this rather plausible but attributes the hypothesis to earlier commentators.

[v] Steven Robinson, “Plato in the Crito” in Jonathon Lavery, Louis Groarke, and William Sweet [eds.], Ideas Under Fire: Historical Studies of Philosophy and Science in Adversity, Fairleigh Dickinson University Press (Madison, WI), 2013: 37-65