Dual-process theories in cognitive and social psychology distinguish between two types of mental processing—typically characterized as fast, automatic, and intuitive (System 1) versus slow, controlled, and reflective (System 2). My central contribution has been to offer a philosophical reinterpretation of this dual-systems framework.
I argue that the distinction between System 1 and System 2 is not between two neural systems operating in parallel or sequence, but between two levels of organization within a single cognitive architecture. System 1 reasoning is subpersonal—fast, automatic processes carried out by specialized neural subsystems. System 2 reasoning is personal-level—intentional actions such as constructing arguments, directing attention, and engaging in various forms of self-stimulation (questioning ourselves, imagining scenarios, rehearsing utterances in inner speech).
On this view, System 2 is a virtual system, heavily dependent on System 1 resources, and constituted by the actions of the person as a whole rather than by a dedicated neural module. This reinterpretation explains why System 2 characteristics cluster together (they are all features of intentional action) and clarifies the architectural relations between the systems. It also opens up connections between dual-process psychology and philosophical issues concerning the nature of reasoning, rationality, belief, and mental agency.
The two-level reinterpretation
System 2 thinking is a culturally transmitted set of habits running on the biological hardware of System 1. Type 2 thinking involves creating external symbols, questioning ourselves, imagining relevant scenarios, and constructing arguments in inner speech. These self-stimulations provide fresh inputs to autonomous System 1 processes, creating what Dennett describes as a ‘virtual machine’.
When we confront a problem that doesn’t deliver a spontaneous response, we can start questioning ourselves: How could I tackle this? What would help? Is there another way of looking at it? These self-stimulations may generate a spontaneous response—more inner speech, other sensory imagery, or an emotional reaction—which reframes the problem or provides a partial solution, prompting another round of self-stimulation. Through cycles of self-stimulation and response, we can work through problems that would otherwise be beyond us.
This process needn’t be pre-planned. We don’t need to know in advance precisely which self-stimulations will solve our original problem. Rather, it is trial and error, though guided by tricks and hunches based on past experience and culturally transmitted knowledge.
Conference and edited volume
In 2006, I initiated and co-organized (with Jonathan Evans) the first international conference dedicated specifically to dual-process theories. Jonathan and I subsequently co-edited In Two Minds: Dual Processes and Beyond (Oxford University Press, 2009), which brought together leading researchers and represented the state of the art in the field. The collection included a historical overview we co-authored and my paper ‘Systems and levels’, which set out the two-level reinterpretation in detail.
I continue to engage with scientific work in the dual-process tradition and explore its implications for philosophical questions about reasoning, rationality, and the architecture of mind.
Key publications
Systems and levels: dual-system theories and the personal–subpersonal distinction (2009) — I argue that the System 1/System 2 distinction corresponds to that between subpersonal and personal reasoning. System 2 processes are intentional actions—argument construction, deliberate attention direction, autostimulation—performed by the person as a whole, not a separate neural system. This explains why System 2 features cluster together and clarifies why System 2 is heavily dependent on System 1 resources. In J. St. B. T. Evans and K. Frankish (eds.), In Two Minds: Dual Processes and Beyond. Oxford University Press.
Technology and the human minds (2021) — I develop the view that System 2 is a virtual mind—a culturally transmitted set of autostimulatory habits running on the biological hardware of System 1. Type 2 thinking involves creating external symbols, questioning ourselves, imagining relevant scenarios, and constructing arguments in inner speech. These autostimulations provide fresh inputs to autonomous System 1 processes. This reinterpretation has implications for cognitive enhancement and artificial intelligence.
Related topics
The two-level mind—Basic mind/supermind and belief
Language and thought—How language enables System 2
Illusionism—Consciousness and the virtual mind
