Feeling, perception, volition, contact and attention — these are called mentality. The four great elements and the material form derived from the four great elements — these are called materiality.
SN 12.2; MN 9
An alternate translation is:
Feeling, perception, intention, contact & attention: This is called name. The four great elements and the form dependent on the four great elements: This is called form. This name & this form are called name-&-form.
Why do we think ‘attention’ (‘manasikara’) is included within ‘nama-rupa’ in Dependent Origination?
Sorry, the only way to answer this question is using Abhidhamma.
Attention is a universal mental faculty which belongs to all mental states. (animal, Deva, Human etc.)
Attention is not considered a Cetasika hence not wholesome or unwholesome.
I personally think manasikara is 'contemplation ’ and sati is attention but that difference is perhaps not too important in this question. If we take the triad of vinnana, Nama-rupa and salayatana, we have what is required for phassa, which is the subsequent step. Therefore we could consider Nama-rupa here as ‘objects’ of one’s process of perception, rather than the result, downstream. Anything that we attended to could become the object of attention in the future.
Dependent origination arises from ignorance &, of particularly relevance is, the absence of mindfulness & wisdom at sense contact. About this, MN 38 states:
On seeing a form with the eye, he lusts after it if it is pleasing; he dislikes it if it is unpleasing. He abides with mindfulness of the body unestablished, with a limited mind and he does not understand as it actually is the deliverance of mind and deliverance by wisdom wherein those evil unwholesome states cease without remainder.
About this lack of mindfulness & wisdom, AN 10.61 states:
Lack of mindfulness and clear comprehension, too, has its nutriment; it is not without a nutriment. And what is the nutriment of the lack of mindfulness and clear comprehension? ‘Unwise attention,’ should be the answer.
When unwise attention (ayonisomanasikāro) prevails, it will make prevail lack of mindfulness and clear comprehension.
I think attention is included within nama-rupa because ignorance conditions/prepares nama-rupa for unwise/ignorant attention, which in turn will make sense contact unwise/ignorant.
Contemplation/thought or attention are one of the basic mental functions. So when nama is defined all mental functions are included in it. The Mahanidana sutta talks of the body and mind of the foetus or baby and its consciousness interacting and how there a death without this interaction. The contemplation is likely to be tainted with ignorance here, but so is yonisomanasikara until someone becomes an arahanth so both ayoniso and yoniso could be included here.
Another reason perhaps due to five feelings wich include body and mind. ----------------
Feelings are commonly classified into three types: Pleasant, unpleasant, and neutral. Pleasant
feeling, in the absence of wise consideration (yoniso manasikāra), leads to attachment, unpleasant
feeling to repugnance, and neutral feeling to ignorance. A pleasant feeling is pleasant while it
lasts but when it changes, as it must, it yields to displeasure—i.e., an unpleasant feeling. An
unpleasant feeling is unpleasant while it lasts, but when it passes a shallow satisfaction arises
which misleads the average person into thinking: “Now, I am all right.” A neutral feeling, in the
absence of wise attention, can foster ignorance and a callous indifference to one’s own and
others’ welfare. If, however, one has developed wholesome awareness based on insight, when a
neutral feeling arises the mind remains in equanimity, undisturbed in all circumstances. This
balanced state of mind is one of the highest forms of happiness.
Relevant to the Abhidhamma, two other classifications of vedanā must be mentioned.
Are you sure? My reading of the translation of DN 15 finds it states ‘nama-rupa’ is ‘description of the mental body and the material body’. Therefore, if the consciousness of the mother is not directed towards her womb or towards her child, a ‘description’ of ‘fetus’ or ‘boy’ or ‘girl’ will not arise. Since I do not know the Pali well, I am happy to be corrected.
More accurately expressed, a neither-pleasant-nor-unpleasant-feeling results in the arising of the underlying tendency (anusaya) to ignorance, as described in MN 148:
Bhikkhus, dependent on the eye and forms, eye-consciousness arises; the meeting of the three is contact; with contact as condition there arises a feeling felt as pleasant or painful or neither-painful-nor-pleasant. When one is touched by a pleasant feeling, if one delights in it, welcomes it, and remains holding to it, then the underlying tendency to lust lies within one. When one is touched by a painful feeling, if one sorrows, grieves and laments, weeps beating one’s breast and becomes distraught, then the underlying tendency to aversion lies within one. When one is touched by a neither-painful-nor-pleasant feeling, if one does not understand as it actually is the origination, the disappearance, the gratification, the danger and the escape in regard to that feeling, then the underlying tendency to ignorance (avijjānusayo) lies within one. Bhikkhus, that one shall here and now make an end of suffering without abandoning the underlying tendency to lust for pleasant feeling, without abolishing the underlying tendency to aversion towards painful feeling, without extirpating the underlying tendency to ignorance in regard to neither-painful-nor-pleasant feeling, without abandoning ignorance and arousing true knowledge—this is impossible.
In other words, the ignorance is always there but the feeling brings it into play.
Ordinarily, if an object is viewed without pleasant or painful feelings (such as when seeing an object that is not understood), the neither-painful-nor-pleasant feeling will give rise to the defilement of confusion (moha), i.e., the craving of wanting to know; wanting to understand. Instead of ‘pulling-in’ the object or ‘pushing-away’ the object, the mind ‘circles-around’ the object, with confusion or curiosity.
Passa > vedana > tanha-moha
Otherwise, if the neither-painful-nor-pleasant feeling is equanimity, such as in jhana, the feeling can still result in ignorance, similar to Hindu or Mahayana Advaita, because ‘Brahman’ or ‘Oneness’ is ignorantly seen rather than anicca-dukkha-anatta.