The psyche for the Greeks is the breath of life, ghost, vital principle, soul, or anima (Peters, Francis, Greek Philosophical Terms: A Historical Lexicon, p. 166). Aristotle addresses two main elements of the soul, movement (kinesis) and perception (aisthesis). Both of these elements have been troublesome points of contention and debate in regards to the soul. Aristotle is on the right track in that the soul may be seen as intertwined with the human body: Homer strayed along the wrong lines and separated the two.
The question of the Human Body (Eliade, Mircea, Encyclopedia of Religion, Vol. 6, God - Ichi, 6:499) and its disposition is intriguing. What survives human life? Organic life exists for a finite period of time, then ceases to be.
I would come down on the side of a dualist which radically differentiates the life principle from all else, as opposed to the homologization of microcosm and macrocosm (which systematically correlates the body with the world outside, p. 499).
"With regard to the first, dualistic physiology posits a radical distinction between base matter and some non-material life principle which inheres only within certain material aggregates for a period of finite duration. the entry of the life principle--be it defined as soul, spirit, breath, warmth, or the life--vivifies and energizes the matter in which it resides: when it departs, death is the result. Such a dualism is implicit in the familiar account of the creation of the first human being in Genesis 2:7 (p. 499).
There are elaborate religious conceptions of origin, existence, and explanations of the soul but what intrigues me is the scientific application of the life force. Energy, insofar as I understand it, does not simply go poof! So what happens scientifically to energy, or a force, and an organic life force at the cessation of death? Ordinarily, and only for the sake of discussion, this is the soul.
David Hume is the skeptic who doubts that "we have any idea of the self" (Stumpf, Samuel Enoch, Socrates to Sartre and Beyond: A History of Philosophy, p. 301). There is no myself that truly exists according to Hume since what I really can catch is only some perception of myself, not the self, itself.