http://dharmafarer.org/wordpress/wp-content/uploads/2010/02/31.3-Anusaya.-piya.pdf
An essay written by Piya Tan, taken from his website http://dharmafarer.org/wordpress/
i remember there's a thread recently regarding morality in the Noble Eightfold Path, here's a quote from the essay which might provide another understanding.
1.5 LEVELS OF DEFILEMENTS. Although all defilements are, in a sense, anusay, the seven mentioned
here are the most prominent (Abhs:BRS 268).43 The first three latent tendencies (of sensual lust, of
aversion, and of conceit) are mentioned in the Sall’atthena Sutta (S 36.6)44 and the Ca,vedalla Sutta
(M 44), the latter of which says: “The latent tendency of sensual desire underlies pleasant feeling. The
latent tendency of aversion underlies painful feeling. The latent tendency of ignorance underlies a neutral
feeling” (M 44.25/1:303). The Majjhima kï‚Œ on this passage says that these three defilements are called
“latent tendencies” in the sense that they have not been destroyed in the life-continuum (bhav’aga) to
which they belong and because they are capable of arising when the conditions are right (MA:Be 2:286).
The Visuddhi,magga explains how this happens by distinguishing three levels of defilements, that is,
as follows:
(1) The transgression level (vï‚´tikamma), a gross level of defilements, where they instigate unwholesome
bodily and verbal action.
(2) The obsession level (pariyuï‚ï‚hï‚Œna), an obsessive level of defilements, where they arise to obsess
and enslave the mind.45
(3) The latent level (anusaya), a subtle level of defilements, where they remain as latent disposition
in the life-continuum (bhavaga).
We had already mentioned the compound adhiï‚ï‚hï‚Œnbhinivesnusaya,46 translated as “the latent
tendencies of mental standpoints and adherences” [1.2]. They are “mental standpoints” (adhiï‚ï‚hï‚Œna)because they are the foundations for the unwholesome mind, and “adherence and latent tendencies” because
they adhere to the mind and lie latent there (SA 2:259; NmA 2:310).
Evidently, this compound embodies the canonical roots for the commentarial conception of the three
levels of defilement. The “mindset” or “mental standpoint” (adhiï‚ï‚hï‚Œna) here refers to the motivation behind
the gross level of transgressive defilement. “Adherence or habituation” (abhinivesa) refers to the
motivation behind the habitual level of addictive or obsessive defilement. The “latent tendencies” (anusay
ï‚Œ) lie dormant in the life-continuum (bhav’aga), ready to rear their ugly heads and wreak havoc at the
slightest instigation.47
The gross level of transgressive defilement is prevented by the observance of moral precepts (sï‚´la).
The habitual level of obsessive defilement is surmounted through mental cultivation (samï‚Œdhi). And the
subtle level of latent defilement is overcome by insight wisdom (pa) (Vism 1.13/5). These three levels
of defilements are often referred to throughout the Commentaries.48