Michael Covel

James Montier in a paper a few years back offered two systems of reasoning:

System One/X-system/Reflexive/Intuitive
Holistic
- Affective (what feels good)
- Associative - judgements based on similarity and temporal contiguity
- Rapid parallel processing
- Concrete images
- Slower to change
- Crudely differentiated - broad generalisation
- Crudely integrated - context specific processing
- Experienced passively and preconsciously
- Automatic and effortless
- Self-evidently valid: “Experiencing is believing” or perhaps wishing is believing

System Two/C-system/Reflective
- Analytic
- Logical
- Deductive
- Slow, serial processing
- Abstract images
- Changes with speed of thought
- More highly differentiated
- More high integrated- cross context processing
- Experienced actively and consciously
- Controlled and effortful Require justification via logic and evidence

He explains:

System X is essentially the emotional part of the brain. It is automatic and effortless in the way that it processes information. That is to say, the X-system pre-screens information before we are consciously aware that it even made an impact on our minds. Hence, X-system is effectively the default option. X-system deals with information in an associative way. Its judgements tend to be based on similarity (of appearance) and closeness in time. Because of the way X-system deals with information it can handle vast amounts of data simultaneously. To computer nerds it is a rapid parallel processing unit. In order for the X-system to believe something is valid it may simply need to wish that it were so.

System C is the ‘Vulcani’ part of the brain. To use it requires deliberate effort. It is logical and deductive in the way in which it handles information. Because it is logical, it can only follow one step at a time, and hence in computing terms it is a slow serial processing unit. In order to convince the C-system that something is true, logical argument and empirical evidence will be required. The table below provides a summary of the main differences between the two systems.