From MN 137 below, we read about the six sense media, one of which is the intellect or mind medium which senses ideas and thoughts.
From MN 137 (translated by Ven. Thanissaro):
"'The six internal sense-media should be known': thus was it said. And
in reference to what was it said? The eye-medium, the ear-medium, the
nose-medium, the tongue-medium, the body-medium, the
intellect-medium. 'The six internal sense-media should be known':
thus was it said. And in reference to this was it said.
"'The six external sense-media should be known': thus was it said. And
in reference to what was it said? The form-medium, the sound-medium,
the aroma-medium, the flavor-medium, the tactile-sensation-medium,
the idea-medium. 'The six external sense-media should be known': thus was it said. And in reference to thus was it said.
It further talks about eighteen explorations of the intellect, basically examining the six sensations for basis of pleasure, pain and neutrality. This includes the idea or thought sensations sensed by the intellect.
"'The eighteen explorations for the intellect should be known': thus
was it said. And in reference to what was it said? Seeing a form via
the eye, one explores a form that can act as the basis for happiness,
one explores a form that can act as the basis for unhappiness, one
explores a form that can act as the basis for equanimity. Hearing a
sound via the ear ... Smelling an aroma via the nose ... Tasting a
flavor via the tongue ... Feeling a tactile sensation via the body ...
Cognizing an idea via the intellect, one explores an idea that can act as the basis for happiness, one explores an idea that can act as
the basis for unhappiness, one explores an idea that can act as the
basis for equanimity. Thus there are six happiness-explorations, six
distress-explorations, and six equanimity-explorations. The eighteen
explorations for the intellect should be known': thus was it said. And
in reference to this was it said.
Discussing "discrimination" specifically, there's AN 5.95 quoted below:
From AN 5.95 (translated by K. Nizamis):
When endowed with five qualities, monks, in no long time a monk
penetrates and intuits the Unshakeable. Which five?
Here, monks, a
monk is one who has attained discrimination of meanings, is one who
has attained discrimination of principles, is one who as attained
discrimination of language, is one who has attained discrimination of
the illuminating qualities (of knowledge), and he reflects upon the
mind as liberated.
When endowed with these five qualities, monks, a
monk in no long time penetrates and intuits the Unshakeable.
The word "discrimination" here is paṭisambhidā. The translator's commentary states as follows. There are more commentaries on other terms in the link to the sutta.
Paṭisambhidā: formed from paṭi- + saṃ- + bhid, where paṭi + saṃ should probably be understood as 'back together', and the verbal root bhid means 'to break, split, sever'. Rhys Davids and Stede
propose that a literal rendering would be "resolving continuous
breaking up", and gloss this as 'analysis, analytic insight,
discriminating knowledge'; moreover, they associate it with the idea
of 'logical analysis' (Pali-English Dictionary, p. 400.2). Bhikkhu
Nyanatiloka similarly renders the term as 'analytical knowledge', but
also as 'discrimination' (Buddhist Dictionary, p. 137). Bhikkhu
Ñāṇamoli voices a divergent view in a note to his translation of in
Buddhaghosa's Visuddhimagga, XIV.8, where he renders paṭisambhidā as
Paṭisambhidā is usually rendered by 'analysis'... But the Tipiṭaka explanations of the four paṭisambhidā suggest no emphasis on analysis
rather than synthesis... 'Discrimination' has been chosen for
paṭisambhidā because, while it has the sense of 'division', it does
not imply an opposite process as 'analysis' does. Also it may be
questioned whether the four are well described as 'entirely logical':
'entirely epistemological' might perhaps be both less rigid and
nearer; for they seem to cover four interlocking fields, namely:
meanings of statements and effects of causes (etc.), statements of
meanings and causes of effects (etc.), language as restricted to
etymological rules of verbal expression, and clarity (or perspicuous
inspiration) in marshalling the other three. (The Path of
Purification, 5th ed., 1991, p. 804, n. 4)
In this translation, I have decided to follow Ñāṇamoli's rendering of
the term. Even so, 'discrimination' does not so clearly capture the
double sense of both 'taking apart' ('analysis') and 'combining
together' ('synthesis') that seems to be suggested by paṭisambhidā.
One kind of epistemological process which involves both of these
activities is 'classification', in which various things, even within a
given class or group (e.g., attha, 'meaning, result', dhamma,
'principle, cause', nirutti, 'language, means of expression'), are
divided and grouped according to their peculiar differences and
similarities with respect to one another. So, while each of the
paṭisambhidā is itself a classification of a kind of knowledge, it is
also possible that each one is also understood to be a kind of ability
to 'classify' correctly the elements belonging to the kind of
knowledge that falls into its scope.
In Visuddhimagga, Buddhaghosa (PTS Vism 438), presents a list of what
he considers to be twelve different kinds of paññā ('understanding',
'wisdom'); the set of catasso paṭisambhidā, 'four discriminations', is
the twelfth of these. He goes on to give an extensive discussion of
them (XIV.21-31, PTS Vism 440-443), which, although of interest, is
very much influenced by the Abhidhamma interpretation of the term:
Buddhaghosa begins by citing the definition of the Abhidhamma Vibhaṅga
(Vibh 293), and then proceeds to follow the subsequent Vibhaṅga
discussion (XIV.24, Vism 441, citing Vibh 293-295). If Buddhaghosa was
indeed the author of the Sumaṅgalavilāsinī (see note 8 below for
details), then his Abhidhamma-based account of the four paṭisambhidā
may well diverge from the original meaning of the term in the period
in which the Suttas evolved and were committed to memory. For the same
reasons, this is very probably also the case for many commentarial
interpretations of earlier Sutta concepts.
Just for comparison, Ven. Sujato's translation of AN 5.95 reads:
“Mendicants, a mendicant who has five things will soon penetrate the
“Pañcahi, bhikkhave, dhammehi samannāgato bhikkhu nacirasseva akuppaṁ paṭivijjhati.
It’s when a mendicant has attained the textual analysis of meaning,
text, terminology, and eloquence, and they review the extent of their
Idha, bhikkhave, bhikkhu atthapaṭisambhidāpatto hoti, dhammapaṭisambhidāpatto hoti, niruttipaṭisambhidāpatto hoti,
paṭibhānapaṭisambhidāpatto hoti, yathāvimuttaṁ cittaṁ paccavekkhati. A
mendicant who has these five things will soon penetrate the
unshakable.” Imehi kho, bhikkhave, pañcahi dhammehi samannāgato
bhikkhu nacirasseva akuppaṁ paṭivijjhatī”ti.