Clinicians would have less trouble assimilating these relationships, which are complex only with respect to their mathematics and the number of causal chains involved, but are conceptually rather simple, if they would familiarize themselves with some elementary philosophical notions about dispositions (see, for example, Broad, 1933; Carnap, 1936-37, 1956; Pap, 1958a, 1958b, 1962, Sellars, 1958). The world consists of four kinds of entities--structures, events, states, and dispositions. There are orders of dispositions, a disposition of order k being, roughly, the tendency to acquire a disposition, and "magnetizable" is a second-order disposition. (Thus, iron is magnetizable, since it can be made magnetic.) If a nonmagnetizable substance can be transmuted so as to be magnetizable, that possibility corresponds to a third-order disposition. The basic idea is, of course, older than modern analytic philosophy, being found explicitly in Aquinas, and in Aristotle before him.

At the molar level (Litttman and Rosen, 1950; Tolman, 1932) of behavior and experience, what the genes provide is dispositions. Most of these dispositions are of higher order than the first; that is to say, they are dispositions to develop capacities to acquire abilities to acquire achievements, these last being dispositions of the first order. For example, a child with the PKU genotype has fourth-order dispositions to develop defective intellectual capacities unless his phenylalanine intake is restricted, and to develop normal capacity under proper dietary regime. His intellectual capacity (say, "first, big factor") is a third-order disposition to acquire numerous second-order dispositions, such as the ability to learn algebra or English, knowing algebra or English being first-order dispositions.

But obviously, this child’s learning of algebra, or his preference for certain stylistic features in speaking English, has a complicated social learning history. An adequate account of either would include reference to his self-concept, his unconscious fantasies, his identification with his professor father or his sonata-writing mother, and the like. None of these experiential factors is a mere "frill’ on genetic explanation. On the contrary, to understand his English-speaking behavior or why he prefers geometry to algebra it is imperative to determine in detail (... as we do in treating a patient on the couch) which kinds of experiences, in which sequence, resulted in his now having such-and such mental content, linked with such-and-such drives, affects, defenses, etc.

The fact remains that a PKU child’s disposition ("ability") to learn arithmetic depends upon the nonrealization of a (pathological) third-order disposition ("incapacity"), which nonrealization, in turn, depends upon an adequate biochemical assessment of a fourth-order (pathological) disposition of genetic origin.

Philosophical confusion about orders of dispositions is responsible for the naive view that "If schizophrenia has a specific genetic etiology, we can’t do anything about it. But psychotherapy does help. Ergo, it cannot have a genetic basis." It is hard for me to believe that psycho-therapists persist in saying this. But I have heard it myself; and I am told that in some parts of the country it is commonly heard. Schizophrenia is a complicated collection of learned social response, object cathexes, self-concepts, ego weaknesses, psychodynamisms, etc. These are dispositions of first or second order. They are not provided by our genes. They are acquired by social learning, especially learning involving interpersonal aversiveness. Assume the mutated gene (a structure) causes an aberrant neurohumor that directly alters signal selectively at the synapse (Meehl, 1962--see Chapter 7 above). Than the gene is a structure; the gene-controlled synthesis of an abnormal substance (or failure to make a certain substance) is an event; the altered synaptic condition is a state ; and the result of the state’s existing at the billions of CNS synapses is an altered parameter of CNS function, i.e., a disposition. But this disposition is a disposition of at least third (perhaps fourth or fifth) order with respect to those molar disposition that are the subject matter of clinical psychiatry and psychoanalysis. Hence an individual’s being characterized by a certain genotype is a disposition of still higher order, because (presumably) the synaptic disposition itself is not an absolutely necessary consequence of the first link of the gene’s action, since it could be avoided if we knew how to supplement the brain’s in adequate supply of magic substance X, or how to provide a related molecule that would bring the parameters of CNS function back to the "normal" base.