Aphantasia as a challenge for Humean abstraction

This paper critically assesses David Hume's imagistic theory of thought in light of aphantasia. Central to Hume's theory is the claim that abstraction requires imaginative operations on individual ideas that are mental representations derived from sensory impressions. We present a challenge to Hume's account of abstraction by drawing on empirical and philosophical insights about aphantasia. Our argument proceeds as follows. If Hume is right, then abstract thinking depends on being able to imaginatively use individual ideas in a specific way. However, since individual ideas in Hume's framework can be identified with mental imagery, individuals with severe aphantasia, who arguably can't imaginatively use mental imagery, should be unable to engage in abstract thought. Yet, they are able to think abstractly. Therefore, Hume's view faces a challenge: abstraction does not seem to require the imaginative use of individual ideas. This reveals a significant limitation not only in Hume's account, but also in imagistic models of cognition more broadly.