  Bolton and Hill worry that whatever background theory the medical model employs, it will require explanations in terms of biological rather than intentional phenomena. They conclude that biological psychiatry can only accommodate disorders in which “intentionality has run out” (2004, 256). If true, this rules out using the medical model to explain the many psychopathologies that appear to involve irreducibly intentional or meaningful processes (cf. Thornton 2007, ch 4). The worry is founded on the assumption that there is an unbridgeable distinction between understanding a phenomenon in intentional terms and providing a causal explanation of it. But the brain is a cognitive organ—and, indeed, a social one. Many disciplines study the effects of healthy cognition on behaviour, and there is no reason to expect that cognition will suddenly become irrelevant to the explanation of behaviour when we study mental illness. For instance, Kendler and Prescott (2006, 148ff) found that “stressful life events” are among the chief causes of depression, that they are especially depressogenic if they involve experiences of humiliation (160), and that humiliation cannot be given a molecular reduction (350). Kendler and Prescott call Major Depression one of the oldest diagnoses in medicine (52) and they are committed to finding specific etiologies. Yet they are happy to employ “classically mental constructs” (350) as parts of their causal models of mental illness.