Original contributors to the enneagram system frequently talk of ‘centers’. Gurdjieff sometimes spoke of three centers, sometimes of five, and sometimes of seven. Briefly, the three basic centers could be said to be the ‘moving’, ’emotional’ and ‘intellectual’, however the first centre really is three centers; a ‘lower storey’ of the organism which includes a true moving centre (controlling movement), the ‘instinctive centre’ which controls internal physiological processes but which also includes processing of sensory data (vision, hearing, smell, etc) and the ‘sexual centre’.
In addition to those are two ‘higher centers’, the higher-emotional and higher-mental. He also spoke of the ‘formatory apparatus’, which is sometimes conceptualized as the lowest level of the intellectual centre and sometimes as being separate and ‘outside’ the centers, relaying signals to each as appropriate.
Gurdjieff also spoke of divisions of centers themselves into a ‘moving part’, ’emotional part’, and ‘intellectual part’. His disciples went on to divide e.g. the ‘moving centre’ into different levels as well [e.g. in Nicholl’s commentaries], but Ouspensky does note in In Search of the Miraculous that Gurdjieff did not go into this in any detail, making it wholly their invention.
Consequently, ignoring their efforts to subdivide the diagram, we could [try to] form an allocation between sub-levels of the centers, and primary type.
For 891, the types are relatively distinct and probably we can say these use different ‘parts’ of the lower storey i.e.
8: sexual centre
9: instinctive centre
1: moving centre.
While Gurdjieff considers the sex centre the ‘highest’ part of the lower storey, a passion related to it is possible in his opinion by it overdeveloping, hence ‘stealing’ the energy of the other centres. Conversely other centres can steal the energy of the sex centre, producing work with a particular vigorousness out of proportion to the actual matter at hand. Compare that to the idea of ‘lust’ as the 8 passion.
Type One conversely is in motion, seeking to improve things (systems, people, organizations). (Conversely, Ichazo linked the idea of ‘perfection’, i.e. the One holy idea, to being able to relax i.e. an absence of movement). From a neurological viewpoint, some reading I have done suggests that anger is in a sense a ‘motor’ feeling – “motor aggression” for example being seen in reptiles that are annoyed, despite these having virtual absence of a higher ‘feeling’ system [limbic system].
9 is sometimes said to be dominated by instinctive centre, while also repressing it (said to be a characteristic of the withdrawn types). 9s do seem to be particularly keyed in to senses of what’s comfortable (sensory input). This can be said to be the more passive of the lower story centers – for instance being ‘engaged’ when you’re trying to get up in the morning and failing, that being an opposition between instinctive and other centers [an example Nicholl uses].
We could potentially go further and try to equate the three sublevels to say which is ‘mechanical’, which is ’emotional’ and which is ‘intellectual’ but that becomes difficult, although it would be very useful if a pattern could be established that is consistent to the other centers. Definitions also affect this – 9 seems the most basic part of the center or the ‘mechanical’ part, but if the most basic part is defined as the ‘moving’ part the answer changes to 1. Likewise, sexual centre seems the most ’emotional’ part [sexual feelings being quite often mistaken for genuine feelings by people] but Gurdjieff also considers this the ‘highest’ part of the centre and notes that intellectual parts do include some feelings in any case.
Jungian correlations: Generally, we could correlate sexual centre to Jung’s “extraverted sensation”. Instinctive perhaps correlates to “introverted sensation”, due to its having a role in sensory data processing. Type One seems the odd one out, but this is for the most part a result of ‘moving’ centre being a quite distinct and different part of the lower storey.