Phillipsian Exchange

In the most recent LRB, Adam Phillips has an article on 'autism' that starts, rather shakily, with a riff on 'exchange' as the bedrock of psychic ease and disease:

Descriptions of mental illness depend on what a society regards as a desirable form of exchange. Behaviour is seen as a symptom (or a crime) rather than a foible or a talent when things deemed to be essential – sex, words, money – are being exchanged in a particularly disturbing way, or not being exchanged at all. Sex with children is unequivocally wrong, and possibly an illness, while exchanging sex for money is merely controversial. In the relatively recent past there was something wrong with men exchanging semen with each other, but nothing wrong with men and women exchanging words with God. Now, for some of the authorities, exchanging words with people who are not there, or using words in a way that makes exchange extremely difficult, or not using words at all, as in psychosis, is an illness or at least a problem. Because these are simply agreements between people and not divine fiats or laws of nature – because diagnoses are now understood to be more or less authoritative forms of consensus – our beliefs about these things are up for grabs in a way that they haven’t been before.

This doesn't strike me as very well thought-through. When person A rapes person B, or when an adult forces sex on a minor, nothing is 'exchanged'; the interaction is all one-way. To suggest that the rapist gets whatever he gets (I was going to write 'pleasure', but that doesn't ring right, somehow) in exchange for the victim's misery is to miss the point about what 'exchange' entails. It's a soggy sort of metaphor, at any rate, on which to build a conceptual model of the psyche.