In Points of Controversy
—Shwe Zan Aung's translation of the Kathāvatthu
— the translator has not translated in full the debate on whether the six āyatanas are kammavipāka, because the Theravādin argument is for the most part the same as that of the previous debate on the question of whether sound is kammavipāka. As they are pretty short I will post both here.
Of sound as Result [of Karma] (Saddo Vipāko'ti Kathā)
Controverted point — That sound is a result of kamma.
From the commentary — Here again some, like the Mahāsaṅghikas, from carelessly interpreting such passages as, "He, by the doing, the accumulating, the augmenting, the abundance of that karma, is gifted with the voice of a Brahmā god," have adopted this view. The argument shows that 'result of karma' is a term applying to mental states only, which have been transmitted by karma, but does not apply to material things. The retinue, for instance, attending a Superman is not a vipāka, or specific result of karma.
From the Katthāvatthu —
Theravādin: [Now what can rightly be predicated of a 'result of karma'?] Such a result is a matter of feeling, pleasant, painful, or neutral; it is conjoined with feeling of these three kinds; it is conjoined with mental contact, feeling, perception, volition, thought; it goes with a mental object; with it go adverting, ideating, co-ordinated application, attention, volition, anticipation, aiming. Is sound anything of this kind? Is it not rather the opposite?
Now mental contact is result of kamma, and of mental contact it is right to predicate any of the foregoing characteristics, and wrong not to. But the opposite holds with regard to sound.
Mahāsaṅghika: But if I am wrong, was it not said by the Exalted One: "He, through having wrought, having accumulated, having piled up, having increased such karma, becomes reborn with the voice of a Brahmā god, like that of the karavīka bird." (DN. iii. 178)? Hence surely sound is a specific result of karma.
[1. Translator's footnote: But the pleasure derived from well-being of this kind is vipāka. Vipāka is essentially a subjective phenomenon, subjective experience, emotional and intellectual. Sound, as object, is something 'other', or external. The importance of speech-sounds for thought doubtless provoked the exceptional position claimed by the heterodox for sound. 'Sadda' means both sound and word; hence, without a qualifying context, sadda means as much vocal sound as sound in general].
Of the Sense-organs (Saḷāyatana Kathā)
Controverted point — That the sense organs are results of kamma.
From the commentary — Here again it is a Mahāsaṅghika belief that, because the sense-organs have arisen through the doing of past actions, therefore they are results (understood as subjective or mental). Of them the sixth, or co-ordinating, sense may at times be such a result, but not the others.
From the Katthāvatthu —
[The argument follows that of the previous dialogue verbatim, the 'sixth sense' (manāyatana) being omitted].
(Points of Controversy 266-7)
But there is a sutta in which Buddha says:
"Now what, monks, is old kamma? The eye is to be seen as old kamma, fabricated & willed, capable of being felt. The ear... The nose... The tongue... The body... The intellect is to be seen as old kamma, fabricated & willed, capable of being felt. This is called old kamma.
(Kamma sutta from Samyutta Nikaya)http://www.accesstoinsight.org/tipitaka
Then in sutta Buddha says that six bases are old kamma, which AFAIUI means these are the results of old kamma (old actions), that is kamma vipaka.
The commentary says that they are not themselves old kamma, but are called "old kamma" through the Buddha's naming them after the condition that produced them. But production by kamma (kammanibatti) is not the same as ripening of kamma (kammavipāka).
How then to understand that Kathavatthu states that "the six sense-bases are the result of kamma" is a wrong view?
As I read it, the point of dispute reported in the Kathāvatthu is one of several in that text that are disagreements over the phrasing rather than the meaning. That is to say, some non-Theravādins had apparently adopted the convention of using the term 'vipāka' to cover everything that results from a morally significant action, rather than limiting it to certain mental phenomena. By contrast, the Theravādin convention was to use other terms (e.g. kammanibbatti, kammasamuṭṭhāna — kammic production, kammic origination) when speaking of kamma-generated rūpadhammas. As such, I would view this particular dispute on kamma as belonging to a different class than those which are genuinely on points of doctrine (e.g. the controversy over whether merit increases with utility).