Why five aggregates instead of just three?

Question

If feeling, perception and consciousness are conjoined or mixed, and it is not possible to separate them or delineate them or disjoin them, then why do we have five different aggregates instead of just three?

What is the significance and usefulness in the teaching to have feeling, perception and consciousness clearly distinguished into three different aggregates? Why were they not combined into a single aggregate?

From MN 43 (translated by Ven. Thanissaro):

"Feeling, perception, & consciousness are conjoined, friend, not disjoined. It is not possible, having separated them one from another, to delineate the difference among them. For what one feels, that one perceives. What one perceives, that one cognizes. Therefore these qualities are conjoined, not disjoined, and it is not possible, having separated them one from another, to delineate the difference among them."

From MN 43 (translated by Ven. Sujato):

“Feeling, perception, and consciousness—these things are mixed, not separate. And you can never completely dissect them so as to describe the difference between them. For you perceive what you feel, and you cognize what you perceive. That’s why these things are mixed, not separate. And you can never completely dissect them so as to describe the difference between them.”

Answer 1

In your question you say, "it is not possible to separate them or delineate them or disjoin them."

But Ven. Thanissaro's translation says: "It is not possible, having separated them one from another, to delineate the difference among them."

So the first point of contention is: is it possible to separate them [feeling, perception, consciousness]?

One reading of Ven. Thanissaro's translation is that A. It is possible to discern the difference between them and B. It is not possible to delineate the difference between them

Here, delineate means to describe or depict. This seems to align with Ven. Sujato's translation: "And you can never completely dissect them so as to describe the difference between them."

There's a difference between experiencing something firsthand (direct knowledge) and conveying that information in words afterwards.

Answer 2

Very good question, which i imagine i will post more about at a later time.

Firstly, about the translations, I suspect the translations of "paññāpeti" as "delineate", "describe" or "declare" may possibly be questionable. "Paññāpana" (from "paññāpeti") is found in SN 22.82 and taken by Bhikkhu Bodhi to mean "manifestation", which fits the context of SN 22.82. Therefore, substituting into MN 43, it might read as: ???????

Secondly, the three types of feelings are related to the arising of the three types of defilements, such as explained in paragraph 30 of MN 148. Therefore, it appears most essential to highlight the feeling aggregate. As said in paragraph 15 of AN 3.61:

Now it is for one who feels that I proclaim: ‘This is suffering,’ and ‘This is the origin of suffering,’ and ‘This is the cessation of suffering,’ and ‘This is the way leading to the cessation of suffering.’

Again, AN 10.58 says:

vedanāsamosaraṇā sabbe dhammā

All dhamma practices converge/meet on feelings.

As we understand by MN 148, MN 38, MN 37, AN 3.61, etc, feeling can arise without there being the arising of craving and suffering. Before the Buddha, I imagine people were seeking a nirvana that was without feeling. Even today on the Buddhist internet, we witness individuals posting obsessively and mistakenly about the cessation of perception & feeling as though it is Nibbana. But the Buddha declared the only possible here-&-now Nibbana and Liberation cannot be without feeling. Therefore, it appears essential to the Buddha-Dhamma, as already explained, to highlight the importance of feeling.

Also, there are conscious experiences that are predominantly feelings, such as jhana. While consciousness arises & lands on such pleasant jhana feelings, obviously the feeling aggregate starts apart in and dominates such jhana consciousness.

Thirdly, as for "perception", at least in relation to what is 'supramundane', there are many suttas about perverted perception and enlightened perception, such as AN 4.49 and AN 10.60. Therefore, it appears to highlight the perception aggregate is also important and it needs to be distinguished from consciousness and feeling.

Answer 3

I think that's true of other teachings too. The links of Dependent Origination are pretty clearly interdependent and happen pretty much simultaneously. Karma isn't as linear and simple as it seems either (for example the current situation and state of mind plays a role in what results appear). And so on.

But I think the teachings are very useful just the way they are. If I recall correctly... Rupa is the body. Feeling is pain, pleasure, neutrality. Perception is the emotions, thoughts, etc. Mental formations is intentions, habits, tendencies, etc. They are simply a very natural and useful way of classifying the clinging we can have.