Ignorance, I-am-ness, desire, hate, instinctive self-preservation, are the taints
The word ‘taints’ means five illusions.
What are the taints by nature and how many are they in number? The sūtra has been given to explain their number and nature. Ignorance, I-am-ness, desire, hate, instinctive self-preservation, are the taints. Their individual characteristics are to be given in the sūtra-s following, and the present sūtra makes no attempt to do more than list them.
(Opponent) Right knowledge, illusion, logical construction, and the other mental processes have been distinguished from one another, but there is no differentiation of the taints from illusion. Why not?
(Answer) Because they are themselves different forms of illusion. They exist only when illusion is there, and so the commentator says, The word means five illusions.
(Opponent) In the sūtra-s which distinguished the classes of mental process, it was said, ‘Right knowledge is either direct perception, inference, or authority’ (I.7), making a division into three; so why did it not there also give the division of this illusion into five in the same way? It was said that illusion is indeed a mental process, and it has been stated, ‘seeing the moon as double is negated by seeing that it is in fact a single moon’ (comm. to I.8).
(Answer) There is no inconsistency, because the taints are not mental processes. For taints are not merely ideas, whereas mental processes are merely ideas. Taints are impurities of the mind, as the disease timira is of the eye. It is from absence of illusory ideas that there is freedom from the impurity of taints.
Now if illusion were no more than an idea, then when taints were suppressed, there would still be illusion in the yogin just as much as ideas of memory or right knowledge. But there is no illusion in those whose taints have dwindled away. So what is called illusion is impurity of the idea, causing distorted perception of things, as in the case of impurity of the eye.
It cannot however be found or spoken of apart from some idea, and so it is described as an idea itself: illusion is a mental process. Again, mental processes were previously divided into tainted or pure (I.5), so a distinction was made there in terms of taints. It would not be reasonable to differentiate mental processes solely in terms of the processes themselves. Further it was declared ‘caused by the taints’ (comm. to I.5), and it would not be logical that what causes mental processes should be itself only a mental process.
As the taints are thus not mental processes, they have not been presented there (in I.8) as divisions of a mental process.
Again it was said, ‘They will be discussed later under impurity of the mind’ (comm. to I.8), showing that taints are not mental processes but only impurities of them. Still, in so far as they relate to the same thing they are figuratively treated as not distinct, as when it is said (Gītā II.38, 39) that as smoke by its impurity covers fire, and as also an embryo and a mirror are covered (by womb and dust respectively) so is knowledge covered by this (Ignorance). It is just the same here.
Quickening to life, these confirm the involvement with the guṇa-s, impose change, stimulate the currents in the body and senses by mutually reinforcing each other, and bring on fruition of karma.
He explains how the ideas are illusory: quickening to life, these … This means that they appear vividly by way of an idea, for they have no action by themselves, any more than a dye without the clothes. They confirm the involvement with the guṇa-s: the involvement is an activity, the fact of something to be done, and they strengthen that. For when they are quickened, the mind is never without something which it has to do.
They impose change inasmuch as they are continually causing change. They stimulate the currents in the body and senses: they heighten the current of activity of the body and of the senses such as the eye. How does this come about? by mutually reinforcing each other: Ignorance and the others become mutually cause and effect in regard to one another.
And they bring on the fruition of karma which is three-fold; they bring on its fruition as birth, life-span and experience.