Chapter 20 Brains or persons? Is it coherent to ascribe psychological powers to brains?


This chapter examines the brain disease model of addiction and its claim that the brain disease involves ‘hijacking’ decision-making, prioritizing, wanting, desiring, choosing, and calculating benefit.

The literature speaks of these capacities as though they were predicates of the brain, or more usually parts of the brain. It is said that the pre-frontal cortex is the decision-making part of the brain, responsible for various forms of cognitive appraisal. There are serious philosophical objections to this, raised in particular by Maxwell Bennett and Peter Hacker, and by Raymond Tallis. These claim that ascribing capacities such as ‘deciding’ or ‘wanting’ to a brain is incoherent, and that these capacities are predicates of persons, not brains or parts of brains. Bennett and Hacker call this the mereological fallacy.

The addicted person’s ability to want things, to decide, choose actions etc. is always to some degree independent of the brain changes that drug use has caused. The brain disease model fails to comprehend how human desires, wants, appraisals, decisions are constitutionally embedded in a socio-cultural context. It is impossible to understand the waxing and waning of substance use crazes and fashions and addiction ‘epidemics’ and the radically varying accessibility of recovery if addiction is characterized and explained in its totality as a brain disease.


Tim Leighton - ORCiD:


Evaluating the Brain Disease Model of Addiction is available from: