Sapratigha means having an opposite. The ten referred to here are the ten which are capable of being ‘struck’ as defined in the previous section – the five faculties and the five organs. So that means the morally neutral dhatus are the five faculties, and the sensory objects of smell, taste and touch.(Commentary) Among the eighteen dhatus, how many are good, how many are bad, and how many are morally neutral?
29c. Eight dhatus are morally neutral
(Commentary) …These are the ten dhatus which are characterised as sapratigha…
29d. Minus visible matter and sound.
What does the text mean by morally neutral? It gives two definitions: (1) not defined as good or bad, and (2) “defined from the point of view of retribution (vipaka)” – so presumably not formative of karma.
Of course this begs the question of what is different about the visible and audible world.
Let’s take the commentary’s three points of description in reverse order, because the last point addresses the question above about the visible and audible.30a. The others are of three types.
(Commentary) The other dhatus can be…good, bad or neutral.
Its third point says that the tangible and audible, mentioned above - rupadhatu and sabdadhatu – are good or bad if they are bodily action or speech, depending on whether they were motivated by a morally good or bad mind. Any visible matter or sound that isn’t the action or speech of a sentient being is morally neutral.
The second point is around dharmadhatu, which it divides into three categories. Dharmadhatu contains all causes of good actions, all dharmas associated with those causes, and all dharmas that issue from those causes, and cessation; these are good. It also contains all causes of bad actions, etc. etc. And third, it contains neutral dharmas such as space.
The first point is about the seven dhatus mentioned in point 16c. (I’m beginning to understand what Malcolm said early on about this text being sequential.) Those are the six consciousnesses and the mano-dhatu which compose, as I’m sure we all remember, vijnanaskandha. The commentary says that these are good when associated with the three good roots, bad when associated with the three bad roots, and otherwise neutral. Unfortunately the three roots are discussed later in chapter 4. I looked up the section and it was the middle of a long discussion of the avnijnapti. So at this point it may be best to just say that it depends on the motivating factor and revisit the question later.