How to Build Thoughts Out of Dust

A Counting Challenge

How might thoughts emerge? In a series of published articles (1, 2, 3), I have introduced a new tool for investigating the nature and origin of thoughts. I call this tool, “The Counting Argument.” My most recent iteration of the argument (in Who Are You Really?) is directly relevant to theories of the emergence of thoughts. That argument challenges the possibility of making thoughts out of (or using) any purely mindless ingredients, like dust or carbon atoms in a brain. If the argument is sound, then mindless matter is insufficient, on its own, to make our thoughts.

In this post, I want to share some recent reflections on this argument—in particular, to consider a possible way out (inspired by a question Joe Schmid asked me). Exploring the way out exposes some minefields that I want to identify. Identifying the minefields can help us see, with greater clarity, what it might take for thoughts to emerge out of mindless debris.

The Argument

First, here is a summary of the general structure of this type of argument (see links above for details and motivations for each step):

1. Counting: there are more possible thoughts than possible mindless grounds of thoughts (e.g., micro-physical states).

   1. This step is supported by (i) a construction principle (by which types of thoughts are definable in terms of being about collections of grounds) and (ii) Cantor’s theorem. (Again, see links for details.)

2. Independence: thoughts (in a class relevant to the Counting premise) can exist independently of each other.

3. Uniformity: individual thoughts are uniform with respect to possible grounds: if any can be individually determined by a mindless ground, all can.

4. Therefore: no possible thought can be individually determined by a mindless ground.*

This conclusion is significant because it implies that your individual thoughts are not determined by mindless grounds.

Two clarifications. First, for ease of presentation, here I use ‘ground’ as short for deterministic, complete ground: that is if x grounds y, then x is sufficient for the existence of y. Second, ‘possible’ and ‘can’ express logical possibility, by which I mean that no contradiction is deducible via any necessary truths of reason. So, Uniformity only requires the logical possibility of uniform grounds. The argument purports to show, then, that it is logically impossible (i.e., contrary to reason) for a thought to have a mindless ground that determines the emergence of that thought (and only that thought).

My goal here is not to defend the argument or address all possible objections. Rather, here I wish to explore what it might take to break the Uniformity premise.

*For those interested in how (4) follows from (1)-(3), I offer two paths. First, click this link for a technical deduction in a structurally similar argument. That argument utilizes extra steps that are unnecessary for the argument here.

Here is a more modest deduction with fewer steps. To start, suppose contrary to the conclusion, that a possible thought T can be individually determined by a mindless ground G. Then by Uniformity, this follows: all possible thoughts can be individually determined by a mindless ground. But there aren’t enough mindless grounds to go around: from (1) and (2), it follows that there are more possible individual thoughts than possible mindless grounds. So, at least some of those thoughts cannot be individually determined by a mindless ground. This result contradicts the previous result that all possible thoughts can be individually determined by a mindless ground. We have a contradiction. Therefore, the starting supposition—that a possible thought T can be individually determined by a mindless ground G—entails a contradiction. Instead, no possible thought can be individually determined by a mindless ground, which is the conclusion of the argument.

Breaking Uniformity

Here is a possible objection to the Uniformity premise. Suppose we put on our mindless-first hats. We view reality as fundamentally mindless (or if we don’t think anything is fundamental, we think some mindless states existed prior to any mental states). From this mindless-first perspective, we could perhaps grant the first steps of the argument: we could suppose that indeed there are possible thought that can’t have any mindless ground. Still, our thoughts can have mindless grounds.

Here is a way we might motivate this break in uniformity. Perhaps, as Joe Schmid suggested to me, mindless grounds can ground thoughts under a certain complexity. Sure, our thoughts can be complex, but they are never infinitely complex. Perhaps, then, the reason that certain possible thoughts that cannot have mindless grounds is that they are too complex; they are more complex than our thoughts could possible be. The idea here is that mindless states have construction limits: it is impossible (logically impossible) for mindless states to have sufficient complexity to ground every thought that someone (or some mind) could consistently have. For this reason, a mindless-first theorist may have independent reason to reject the Uniformity Premise.

Obstacles

I appreciate the prospect of someone having independent reasons to break uniformity. As with any argument, people will have varying background considerations to weigh. Moreover, even if breaking uniformity strikes someone as initially costly (to some degree), that person could still have independent reasons to pay that cost.

That said, there are some significant obstacles I want to draw attention to. Seeing the obstacles can help us to see more of what is at stake. I will highlight 3 obstacles to breaking uniformity.

Obstacle 1: Reduction entails Uniformity.

At least some philosophers who accept a mindless-first view are already committed (I don’t mean psychologically, but by logical implication) to accepting Uniformity. In particular, on a reductionist view (such as identity theory), every mental type reduces to a (third-person) physical type. In a mindless-first frame, the “physical type” is not itself analyzed in terms of irreducible mentality (per idealism). Instead, it is analyzed in terms of more fundamental types (e.g., c-fibers firing), which are not themselves grounded in irreducible mental states. On this account, every mental type—whether actually instantiated or possibly instantiated—is identical to a mindless-grounded type. In other words, thoughts are uniform with respect to the possibility of a mindless ground—which entails Uniformity.

Obstacle 2: Non-Reductive Physicalism does not break Uniformity.

Of course, not all mindless-first theorists are reductionists. Another idea is that thoughts are analyzable in terms of irreducibly mental types (e.g., concepts), which in turn emerge given the right mindless grounds. Then the mind emerges from the mindless.

This “emergence” picture, however, is still fully compatible with Uniformity. Indeed, a typical mindless-first view is that mentality is only emergent given a certain organization of items (e.g., neurological activity in a brain), which themselves are most fundamentally grounded in non-mental items (e.g., atomic motions). In that case, a possible thought can only emerge if certain mindless grounds are in place—just as Uniformity says!

To break uniformity, therefore, we need more.

Obstacle 3: There is a problem of density.

Let us consider a more ambitious idea: we can break Uniformity if we suppose that certain thoughts can emerge without any brain—so long as those thoughts are sufficiently complex. The idea here is that there is a threshold of complexity, such that thoughts of that complexity are buildable only from mental states (without mindless grounds). In short, complexity makes the difference. 

However, I think there is a very strong reason to think that complexity does not make the difference. The reason is this: for any level of complexity, there are still too many thoughts at that complexity for each to have a mindless base. That’s because for any complex mindless grounds (e.g., a brain state composed of mind-independent particles), there is a similarly complex thought about that state plus many other similarly complex thoughts (replacing the mindless contents with other qualities of consciousness). The result is that there are too many thoughts of a similar complexity for each to have its own mindless base.

To illustrate further, imagine there is an infinite road speckled with rocks of various sizes and shapes. Interspersed between the rocks are little holes in the ground. On average, you see ten rocks per hole; suppose this density of rocks to holes holds throughout the entire infinite path. In this case, while it is true that the cardinality of the rocks is the same as the cardinality of the holes, the density on the path differs. At each step on the path, there are more rocks than holes at that step. This road illustrates the greater density of thoughts to mindless states for any degree of complexity.

Now consider the hypothesis that every rock fits perfectly into a unique hold in the ground. That hypothesis, while theoretically possible, is unlikely given our observations. It is more likely that if all the holes were filled with a rock, there would still be rocks leftover on the path. This illustrates the idea that if all brain states (or mindless grounds) of a given complexity were to ground a thought, there would still be buildable thoughts of that same complexity left over. The density of thoughts at any given complexity is too great for them to all have their own unique mindless base.

If that’s right, then complexity can’t be the whole story. The break in uniformity would also occur for thoughts of the same complexity. Going the other way: if there is no break in uniformity for thoughts of the same complexity, then thoughts of the same complexity can have the same category of base (mental or mindless). In other words, we still get the result that buildable thoughts are in the same boat as buildable thoughts of the same complexity: they all have a mental basis (if any).

Final Thoughts

To get around these obstacles, I think what we need is an independent reason to think that certain thoughts of the same complexity can have mindless grounds, while others cannot. 

Here is one way I think someone from a mindless-first view could develop that reason (in principle). They could combine their view (that mindless states ground mental states) with the previous steps in the argument. From here, they could infer that there must be a break in Uniformity, somewhere, even if no one sees exactly why or where. This is the best path out, in my view, for a mindless-first theorist.

However, I conclude this assessment by placing an orange cone on this path away from Uniformity. While I do think someone could motivate breaking Uniformity (from their total commitments), I think the break comes with a cost. In my view, Uniformity is an intuitive principle about the category of things that make thoughts. I find it quite plausible that thoughts have the same logically possible kinds of grounds (whether mental or mindless). Breaking this uniformity strikes me as a steep cost, like the cost of supposing that some numbers could be made out of glass but not others; I don’t think any numbers can be made out of glass, but if some could, I would expect they all could be made out of that same type of material. Same for thoughts: if any thoughts could (without contradiction) be made out of glass or any other kind of materials, I expect they all could (in principle).

In short, Uniformity has independent support (including from a mindless-first perspective), and there are obstacles to breaking uniformity.

My own take away from the counting argument is that thoughts are made (grounded) in the context of a mind (a realm of consciousness). I take it that we can independently identify grounds of thoughts in terms of mental states (states of mind), which are knowable in first-person experience. I grant that a mindless-first theorist could theoretically accept this result by supposing that some mindless things have a power to (non-deterministically) cause a mind. However, setting aside the other construction challenges (materials problem, causal exclusion problem, binding problem, etc.), it seems to me the extra posit of mindless things that could cause a mind is unnecessary, since everything we know in consciousness can be analyzed more simply in terms of a mind-first ontology.

Another way to think about it is in terms of possibility spaces. Take sand. The possibility space of possible sand arrangements is larger than the possibility space of possible sand castles. This is a powerful reason to think that sand castles ultimately come from (or depend on) sand arrangements, not vice versa. In the same way, if the possibility space of mental states is larger than the possibility space of (say) material states (e.g., brain states, fields, etc.), then that’s a powerful reason to think that material states ultimately come from (or depend on) mental states.

Still, there is more to explore on this path, and perhaps navigating this territory will bring into greater view what it takes for our thoughts to emerge, whether out of mindless dust or out of our own minds.