A rational and mindful approach of mind is stated in DN22. It is to have an eye for how mind can feel very different from moment to moment or day to day. It can be felt as extremely contracted or as open as the sky; rigid or flexible, freed and unfreed, supreme and not supreme, expansive, non-expensive etc (DN22)
This describes states of mind. Those can rapidly change.
These states of mind, they arise and cease, day in day out. It depends on what defilement come flowing (AN1.51) in the mind. A worried mind feels very different from a mind without worries.
The mind with hate really becomes very narrow, restricted, heavily burdened. The same with greed and delusion. Like defilement they coarsen the mind. These mind states are mentally felt, as it were, and often also bodily ofcourse in bodily tension etc.
But what happens when there is no greed at all, no hate at all, no delusion at all incoming?
Is that pure mind still felt like the angry mind can be felt, or the jalous mind etc?
Is it really an aggregation?
Is this pure mind, mind without limits (AN10.81), still a state of mind that can be seen coming and going