Sutta 1>2-1>
1> 'Eye and light, ear and sound, nose and scent, tongue and taste, body and touch, mind and dhamma are called 'the all'.
Eye, ear, nose, tongue, body and mind are called six sense organs in all.
Eye, nose, tongue and body are called five sense organs in all.
Light, sound, scent, taste, touch and dhamma are information emanating from outside world and objects of the six sense organs.
Such information from outside world as light, sound, scent, taste and touch reach the five sense organs to be transformed into electric pulses.
Brahminism prevailed when Gotama Buddha was born in India, which preached such things as 'the God, the soul, the former life or life after death and, the transmigration of the soul.
Human beings are unable to recognize existence of such things as the God, the soul, former life or life after death and the transmigration of the soul. Gotama Buddha, decisively rejecting mysticism of Brahmanism, declared in stead, 'eye and light, ear and sound, nose and scent, tongue and taste, body and touch, mind and dhamma are called the all'. He stands on empiricism.
Eye and light, ear and sound, nose and scent, tongue and taste, body and touch, mind and dhamma are called the all. I myself call the all, light and eye, sound and ear, scent and nose, taste and tongue, touchand body, dhamma and mind.
light------eye sound------ear scent------nose taste------tongue touch------body dhamma-----mindchart 1
Light, sound, scent, taste, touch, dhamma and eye, ear, nose, tongue, body, mind are called the all. Eye, ear, nose, tongue, body and mind are called the six sense organs. Information from outside world and six sense organs are called the all.
According to Gotama Buddah, information from outside world and six sense organs are the all of the universe. I think this is an overstatement but what he asserted was the empiricism, the very starting point of Gotama Buddhism.
2-1> 'Body, [sensation, perception, formation, consciousness] are the things to be understood'.
Standing on empiricism, Gotama Buddha preached that 2-1> 'Body, [sensation, perception, formation, consciousness] are the things to be understood.
Body means material, human body or my own body. Sensation, perception, formation, consciousness mean mental phenomema of human brain, that is, mental phenomena of my own brain. Body, [sensation, perception, formation, consciousness] mean body and brain. In other words, human being, and me myself.
Gotama Buddha taught 'you should understand yourself based on your own experience'. Aiming at understanding myself, I began observing myself. In natural science they first observe the objects to understand their true nature.