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. 

A Nyāya-Vaiśeṣika Argument for the Existence of God

Historical Context

The different philosophical traditions in classical Indian thought are usually categorized under the labels of orthodox and heterodox. The orthodox traditions accepted the scriptural authority of the Vedas, while the heterodox ones such as Buddhism and Jainism did not. Nyāya and Vaiśeṣika were initially two different orthodox schools. Nyāya was mostly concerned with logic, reasoning and epistemology. Vaiśeṣika focused on metaphysics and identifying the different kinds of substances that ultimately exist. By the eleventh century, these two traditions had merged into a single school, which came to be known simply as Nyāya-Vaiśeṣika (NV henceforth). Apart from a few academic philosophers, the NV tradition is basically extinct today. Historically, however, they were extremely influential and made a number of important philosophical contributions.

Of all the theistic systems in India, NV had the greatest confidence in the scope of natural theology. They came up with a number of arguments for the existence of Īśvara (“the Lord”), and were engaged in a series of polemical debates with other thinkers, their primary adversaries usually being Buddhists. I will go over their most well known argument for theism in this essay.

What the Argument is Not

Before I lay out the the argument, I want to make a few preliminary comments on what the argument is not, since this is often an issue of confusion.

The argument is not like the popular Kalām cosmological argument, which states that everything that begins to exist must have a cause, and that if you trace the chain of causes you eventually get to an uncaused cause that explains the beginning of the universe. Indeed, the NV system holds that a number of entities are eternal and uncreated. These include the atoms of different elements, time, space, universals, individual souls, and of course, God.

The argument also does not belong to the family of arguments from contingency, which conclude that there is a necessarily existent being that explains why anything at all exists. The NV thinkers were not committed to the view that everything that exists has an explanation for its existence. Finally, the argument is not like familiar teleological arguments that draw on observations of biological complexity to infer that an intelligent designer exists.

That said, the NV argument does bear some resemblance to all of the above arguments. It is therefore best understood as a hybrid cosmological-teleological argument. The argument points out that certain kinds of things require an intelligent creator that has the attributes traditionally assigned to God.

Overview of the Argument 

The argument can be stated as follows1:

(P1) Everything that is an effect has an intelligent maker.

(P2) The first product is an effect.

(C)  Therefore, the first product has an intelligent maker.

The argument as spelled out here is a little different from the way the NV philosophers usually framed it, primarily because they had a more elaborate way of laying out syllogisms. But that need not concern us. The important point is that the argument is valid – if the premises are true, the conclusion does follow. But what are we to make of the premises?

Some terminological clarification is in order before we can assess the premises. By an effect, defenders of the argument refer to a composite object – i.e., an object made of parts. Buildings, rocks, mountains, human bodies are all examples of effects. Recall that NV philosophers were atomists, and since atoms are indivisible and indestructible, they do not count as effects.

The first product refers to the simplest kind of effect that can be further broken down into atoms. In the NV system, dyads – imperceptible aggregates of two atoms – were seen as the first product. But again, that need not concern us. All we need to know is that the first product is the smallest unit that is itself further divisible. We can now move on to scrutinize the premises.

Support for the Premises 

P2 is necessarily true, since the first product is defined as the simplest kind of effect. Things get interesting when we consider the first premise. P1 states that every effect has an intelligent maker, where an intelligent maker is defined as an agent who

(i) Has knowledge of the components that make up the effect;

(ii) Desires to bring about the effect; and

(iii) Wills to do so.

The obvious question then is: why believe that every effect has an intelligent maker?

The support offered for P1 is inductive. NV philosophers defend P1 by pointing out that we have a very large number of examples that confirm it. The classic example is that of a pot. We observe that pots have an intelligent maker: the potter who is aware of the material out of which the pot is made (the clay), desires to make the pot, and wills to do so. Atoms are deliberately excluded from P1 since they aren’t effects, and hence cannot be seen as counterexamples. Given this, defenders the argument claim that the numerous confirming instances (as in the case of the pot/potter), entitle us to accept P1 as a general principle.

Responding to Objections

Philosophers in the NV tradition were aware that the argument was extremely controversial, and came up with a number of interesting responses to common objections. I will go over three of them here.

Objection 1: Counterexamples to P1

The most common objection is that there are obvious counterexamples to the first premise. Rocks, mountains, plants – these are all made of parts, and yet, don’t have a maker. Thus, P1 is false.

The NV response is to say that this objection begs the question against the theist. The mere fact that we don’t immediately observe a maker in these cases does not establish that a maker was not at least in part involved. For the maker could, after all, be spatially or temporally remote2 from the effect.

NV philosophers press the point by insisting that if direct observation of the cause was necessary, then even ordinary inferences would be defeated. For instance, we wouldn’t be able to infer the presence of fire from smoke if the fire wasn’t immediately observable. But of course, the fire could be a long distance away. Similarly, if we happen to come across a pot, we wouldn’t suspend judgement about whether it was made by a potter simply because we didn’t directly and immediately observe the pot being made by one. The potter could, after all, be in a different town, or even be dead. In other words, this objection proves too much, since it would render everyday inferences that we all rely on unjustified.

Objection 2: The Possibility of Counterexamples to P1

At this point, we might be willing to concede that we can’t rule out the existence of a maker for things like rocks and mountains. However, since the maker isn’t directly observed, the theist can’t be sure that a potential counterexample doesn’t exist either. It may be true that we have observed several instances of effects that have makers, but the possibility that there exists a counterexample means that P1 is at the very least unjustified, if not shown to be false.

Once again, the NV response is that the objection proves too much. The mere possibility of a counterexample is not reason enough to give up on the first premise. Consider, again, the example of smoke and fire. The mere possibility that there may have, at some time in the distant past, or in a faraway land, been an occurrence of smoke without fire does not give us enough reason to reject general fire-from-smoke type inferences. Unless we are willing to give up on induction entirely, there is no reason to reject P1.

The skeptic is also accused of another inconsistency at this point. Why does the skeptic not doubt that material things have material causes? If someone who is skeptical of P1 came across an object they had never seen before, they probably would not doubt that the object had been made out of pre-existing matter. And yet, the support for the belief that material objects have material causes is also inductive. The skeptic must provide some principled reason to reject P1 while also believing in material causes without the reason collapsing into the first objection which has already been refuted. Since the skeptic has not done this, they have failed to show that we must not accept P1.

Objection 3: The Gap 

Many arguments for theism face what is sometimes called “the gap” problem. In other words, even if these arguments establish the existence of an intelligent maker, there is no reason to think this creator has any of the attributes traditionally assigned to God. A skeptic may point out that in all the cases of intelligent makers we have observed, the makers were embodied agents. The makers were not omniscient, uncreated or eternal. So there is no reason to suppose that the argument, even if successful, gets us to God. At best, it can establish the existence of some kind of intelligent maker, but any further claims about the omniscience or eternality of the maker would not be justified, since these properties are not observed in any of the cases we discussed.

Predictably, the NV response is that the criterion for inference being proposed as part of the objection is too strong, and would defeat many of our everyday inferences. In most inferences we make, we go beyond the general cases, and can justifiably infer special characteristics depending on the context. To go back to the commonly used fire-and-smoke example, if we observe smoke rising from a mountain, we don’t merely infer that there is fire. Rather, given the specific context, we infer that there is fire that has the property of being on the mountain. In other words, it isn’t fire-in-general that is inferred, it is fire-on-the-mountain. Similarly, based on the specific context, we can conclude that the maker of the first product has certain characteristics.

Since the maker exists prior to the first product, it must be uncreated. It cannot have a body, since bodies are made of parts, and this would simply introduce a regress that would have to be terminated by a creator that is not made of parts. Thus, the maker must be disembodied and simple. Since it is simple, it cannot be destroyed by being broken down into its constituent parts, and hence must be eternal. Since it has knowledge of all the fundamental entities and how to combine them, it must be omniscient. Finally, simplicity favors a single maker over multiple agents. The intelligent maker thus has many of the attributes of the God of traditional theism.

Conclusion 

The argument, if successful, does get us to a God-like being. P1 is the controversial premise, and as we have seen, NV philosophers respond to objections by essentially shifting the burden of proof on to the skeptic. This can seem like trickery, and indeed, that’s how the influential 11th century Buddhist philosopher Ratnakīrti characterized it in his work Refutation of Arguments Establishing Īśvara, which is arguably the most thorough critique of the Nyāya-Vaiśeṣika argument. Either way, it is at least not obvious that the first premise can be easily rejected, so the skeptic must do some work to justify rejecting it. I may go over Ratnakīrti’s criticisms in a future essay.

References 

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

[2] The terminology I’m using is based on Parimal Patil’s translation of the original Sanskrit terms in Against a Hindu God: Buddhist Philosophy of Religion in India.