I hesitate to respond to Victor Reppert’s latest riposte (April 19) on his Dangerous Idea blog, since BDK and others have already hashed it out with considerable sophistication and subtlety. My aim here, however, is not to refute Victor (knockdown refutations in philosophy occupy a shadowy ontological niche somewhere between very rare and nonexistent), but to understand as clearly as possible just where our differences lie. In my experience, intractable disagreements come down to ground-floor, big-ticket items like a clash of fundamental intuitions or a divergent understanding of some basic point—or maybe just sheer cussedness. Therefore, I do not think the crucial issue will be a technical one. It will not come down to a disagreement between, e.g., type vs. token physicalism or the proper deployment of Lewis-Ramsey sentences, but will be something much more basic. It is like debating William Lane Craig on the Kalaam arguments. You can discuss the details of physical cosmology ad nauseam, but, as Craig admitted in our debate at Indiana University a few years back, ultimately it comes down to conflicting metaphysical intuitions. For Craig, whatever begins must have a cause. To me, an uncaused initial state of the space/time universe seems quite a reasonable postulation—at least as reasonable as postulating a timeless, supernatural creator. I think something this basic comes between me and Victor.

The crucial issue seems to emerge in a quote from my previous posting and Victor’s response.

Parsons:

“When we say that Sam was convinced by Krugman’s arguments it seems to me perverse to attribute some very (I think in-principally) mysterious kind of causal power to the sense or propositional content of Krugman’s arguments. Attributing causal powers to Fregean Sinn (meaning), if this is what Victor wants to assert, just seems to me a straightforward category mistake. It is like saying that the set of all integers broke the deadlock between NFL players and owners. No, to say that Sam was convinced by Krugman’s arguments means that Sam considered Krugman’s claims, examined the supporting reasons, weighed them in the light of prior knowledge and norms of good reasoning, and judged that these were persuasive. However, considering Krugman’s claims, examining the supporting arguments, evaluating them, and judging them to be persuasive are things that Sam does with his brain, and happenings in Sam’s brain, being physical events, can cause things.”

Reppert:

“Well, if Sam’s considering and accepting Krugman’s arguments is a brain process, it looks like we are going to end up attributing properties to Sam’s brain that are going to violate the causal closure of the physical. If Sam finds Krugman’s arguments persuasive, one of the things he has to be persuaded by is the logical connection between the Krugman’s premises and his conclusions. To be aware of something is to be causally influenced by it. So, yes, my awareness of a stop sign causes me to stop, not the stop sign itself. If I don’t see the sign, I’ll barrel right through. But, the stop sign has to cause my awareness of the stop sign. And if the physical is causally closed, then everything that I am aware of has to be also physical, and by physical I take it we mean that it has a particular location in space and time. A logical relationship has no particular location in space and time, and so if I am aware of a logical relationship, and that logical relationship affects my brain, then the causal closure of the physical has been violated, because something that has no particular location in space and time is bringing it about that I think certain things.”

I think the crucial sentence is this:

“To be aware of something is to be causally influenced by it.”

Now, I agree that (putting it very roughly and crudely) things cause my awareness of them. The physical properties of the stop sign must be adduced in an adequate causal account of my awareness of it. What about Sam’s awareness of the logical connection between Krugman’s premises and conclusions? Must not that logical connection likewise cause Sam’s awareness of the logical connections? Victor thinks so and I do not. Why not? What is the difference between the two cases? A stop sign is a thing, but I do not regard the logical connection between premises and conclusion as any kind of a thing at all. As Victor notes, logical relations have no location in space and time. I would add that they have no physical properties at all and since, in my naturalistic view, causal powers exist only in virtue of physical properties, logical relations and other such abstracta can have no causal powers at all.

OK, then, I think that I am finally seeing the essential divide (or at least one of them): I hold that brains could have the power to grasp certain truths even though the objects of that knowledge—those truths—have no causal powers to influence brains or anything else. In other words, I disagree with Victor that it is always or necessarily the case that “to be aware of something is to be causally influenced by it.” When the “something” we are aware of is, for instance, an a priori truth, then the claim seems to me to be obviously, and necessarily, false. To say that my awareness of an a priori truth (which awareness I conceive as a physical state) has causal efficacy certainly seems plausible, but to attribute causality to the a priori truth itself just sounds like gibberish to me—whatever one’s philosophy of mind. That is, whether the knowing self is a Cartesian mind, or a physical brain, or something else, the idea that propositional contents or a priori truths might cause anything seems a bizarre notion to me—a gross category mistake like saying that the number seven is in a bad mood.

I guess, then, what Victor really needs to explain to me is why he holds that it is a necessary truth that “To be aware of something is to be causally influenced by it” when no restrictions or qualifications seem to be placed on the nature of that “something.” This makes sense if the “thing” is a thing—a physical object, but not if the object of knowledge is, say, an a priori truth or a propositional content.

[Note to BDK: In this and my previous postings on this subject, I am not offering or intimating any theory of the nature of propositional contents. I am trying to accommodate what it seems to me that Victor is saying.]