According to Searle in Mind, Language and Society, the mind-body problem is a “big” question with an “obvious” solution that presents “no difficulty.” Who knew? He starts by delineating consciousness, intentionality, subjectivity and mental causation as four phenomena of mind that must be explained in accord with explanations of the body. Just what about “body” is up for explanation is left for the reader to fill in, but presumably it is more than just ‘extended thing in motion in space’, since biology and not just physics explains it. Regardless, for Searle, mind and body both can be explained by biology “just like” digestion and bile secretion can be explained by it. Seriously: “just like.” As for “mind” and other “mental phenomena,” they too are explained by biology “just as” digestion and the secretion of bile can be explained (surely this makes one wonder why digestion is almost completely understood but embodied conscious is not). Anyway, in somewhat more detail, the explanation is two pronged. First, mental phenomena are “caused by processes going on in the brain”. Second, they are also “just [realized] features of the brain”. Additionally, mental phenomena “start” at the nerve endings of the senses and “end” “inside” the brain. This dual explanation of mind/body (with its auxiliary) provides for Searle “a perfectly ordinary model for explaining the puzzling relationship between the mind and the brain,” in that the micro-features of causation, neurons, are realized in the system, the brain, just as atoms in lattice structures cause a property realized (solidity) in large bodies. We are to draw from this “simple” explanation that “the mind and body interact, but they are not two different things, since mental phenomena just are features of the brain.” He goes on to point out that mental phenomena can thus cause physical phenomena, without specifying whether this causality goes back “out” of the brain to physical objects in the world or just remains “inside” it as a physical/mental object.
“Obvious” and “simple” explanations to “big” problems ought to throw up a big red flag, and this one does not disappoint. The reader is left to solve for himself how mind and body, or rather mind/body, which is not two things, can ever interact. Inter-action requires at least two elements. So what are they, and what causes the interaction? Since mind/body is not two different things—since it is one thing inter-acting—does it cause itself? No, Searle himself rejects causa sui out of hand, so the “brain/mind” does not cause itself—yet it remains causal both in an inward and an outward direction. The recourse to causa sui is also ruled out by mental process “starting” at the nerve endings of the senses and “ending” in the brain (though in truth, this would only rule out mental process about external things outside the brain, leaving perhaps the brain/mind-that-is-one-thing-interacting-[with itself]-without-causing-itself to cause intentional thoughts about its own mental phenomena, as those would both “start” and “end” in the “inside” of the brain). Searle’s explanation from microstructures like neurons causing properties like mind is no help either for explaining how “one” thing inter-acts, since in that example from physics, “solidity” does not “inter-act” with molecules in lattice structures. Rather it is the interaction of lattice structures. No matter how you slice it, one thing inter-acting simply makes no sense, and even if it did, this inter-action is not going to get along with any useful notion of causality, if one rejects– as Searle does– this inter-action causing itself. So the obvious simple solution is not without its fatal problems.
Descartes at least bequeathed to us two substances, soul and body, interacting at the pineal gland in an operation sanctioned by God to insure reliable knowledge. From him we got two limited but at least provisionally clear definitions of both mind and body, with a lot of divinity thrown in to make the whole system work (what’s a world without God, right?). These ideas stand in much internal consistency within his system, however much one likes or dislikes the starting point or consequences of that system. However, Searle would have us extend those definitions to four features for “mind”—an improvement, since Descartes only gave us one—and take away one for “body”—not an improvement, as living versus inanimate bodies remains to be distinguished, since both physics and biology are valid. Then he would have us disallow that either is a substance, leaving us instead with a blind conjunction that both “naïve physicalism” and “naïve mentalism” are “true.” Again, who knew? One usually finds in philosophy and science that the naïve solution is not true (why else do philosophy or science?), so score one for the good sense Descartes said was so evenly distributed among mankind, such that people never wished they had more of it than what they already have. Searle apparently never has. To boot, “mind/brain,” such as it is for Searle, can even cause physical phenomena, which is more than we get in the way of human potential from Descartes, who limited the causation to part of the way from things to mind, stopping, as it were, before ‘impacting’ the soul. Can Searle’s mind/brain really move mountains?
‘Mind/brain as one thing inter-acting with itself without causing itself while itself causing physical events in the world’ is just about what one would expect from a “simple” answer to a “big” question that is also “obvious.” One is much better off with Descartes, if only for aesthetic reasons. But in case one is greedy, one could also ask, like Descartes did of his own account: if mental process are inside the mind/brain and physical things are outside it, how do we come to know the physical things which “start” the chain of events at the nerve endings “outside” the brain and “end” up as mental processes “inside” it? How do these mental processes arise? Are they like the physical processes which ultimately cause them? Are they like the mental processes/physical processes that apparently cause themselves as the mind/brain comes to reflect on its own intentionality and subjectivity? Is knowledge just this process, or something else, and how can we tell? Since unanswered questions are not really objections to an explanation unless they are both unanswerable and necessary for the explanation to work, it is left for the reader of both Searle and this rumination to decide if some account of knowledge is also necessary in an “obvious” explanation of what we know to be true about mind and body, which are one and the same thing, yet interacting. Perhaps that explanation will be both simple and obvious without throwing up big red flags of its own (the anus is not holding out for that).
 Since it wasn’t holding out, the anus later discovered that Descartes himself foresaw the problem with Searle’s account as it is addressed here. In a letter to Princess Elizabeth (28 June 1643), he notes: “it does not seem to me that the human mind is capable of forming a very distinct conception of both the distinction between the mind and the body and their union; for to do this it is necessary to conceive them as a single thing and at the same time to conceive them as two things; and this is absurd.” He also says that the union between the two is best understood in “ordinary life and conversation” as opposed to formulated through “the study of things which exercise the imagination”—so living the connection is the best way to understand it. The anus claims independent discovery despite not offering the rather sublime idea of living the union as opposed to “solving” it as a “problem.”