Mr. Seek wrote: ↑Sat Jan 02, 2021 10:08 pm Is there a description of right mindfulness (as part of the 8-fold path) out there in the five nikayas that matches with the description of mindfulness as found in DN 2?
Also, what do you think about the obvious difference between the two? DN 2 says being mindful is simply being aware, being wakeful, attentive, etc., during daily activities. ...
Look at SN 47.2 carefully. It delineates the difference between sati and sampajano. What DN 2 is calling S&S (sati and sampajano), SN 47.2 explains as the sampajano is the lucid-discerning aspect of moment to moment awareness. It further explains, that what sati does is remember Dharma. And the default value of Dharma that is remembered, is the four satipatthana.
The pre buddhist defintion of sati is memory/remembering. See SN 48.9 for sati-indriya.
Unfortunately this isn't all that clear with explanations on sati scattered around over the nikayas. It takes time to study the suttas carefully and connect the dots. But SN 48.9 and SN 47.2 will explain that part of the question.
The other thing you're confused about, and most Buddhists are, including famous Buddhist monks and scholars, is that sati and jhana and viriya are all operating simultaneously. See MN 78 and MN 125 especially, where the first jhana is deliberately omitted because the satipatthana that takes kusala thoughts as its object is describing first jhana already.