|We get a hint of the relation between these three, spirit,
soul and body, in the words of The Secret Doctrine.
"Life we look upon as the One Form of Existence, manifesting in what is called
Matter; or what, incorrectly separating them, we name Spirit, Soul and Matter in man.
Matter is the Vehicle for the manifestation  of Soul on this plane of existence, and
Soul is the Vehicle on a higher plane for the manifestation of Spirit, and these three are
a Trinity synthesized by Life, which pervades them all."
- Blavatsky, H. P., The Secret Doctrine, Vol. I, pp. 79, 80.
The soul, the self are synonymous terms in Oriental literature. The main treatise upon
the Soul, its nature, purpose and mode of existence is that most famous of all the Eastern
Scriptures, the Bhagavad Gita. Deussen summarizes the teaching as to the Atma, the
self or soul, as follows:
"If for our present purpose we hold fast to this distinction of the Brahman as the
cosmical principle of the universe, the atman as the psychical, the fundamental thought of
the entire Upanishad philosophy may be expressed by the simple equation:
Brahman = Atman
This is to say - the Brahman, the power which presents itself to us materialized in all
existing things, which creates, sustains, preserves, and receives back into itself again
all worlds, this eternal infinite divine power is identical with the atman, with that
which, after stripping off everything external, we discover in ourselves as our real most
essential being, our individual self, the soul. This identity of the Brahman and the
atman, of God and the soul, is the fundamental thought of the entire doctrine of the
The atman is, as has often already been pointed out, an idea capable of very different
interpretations. The word signifies no more than 'the self,' and the question then arises
what we regard as our self. Three positions are here possible, according as by the atman
is  understood (1) the corporeal self, the body; (2) the individual soul, free from
the body, which as knowing subject is contrasted with and distinct from the object; or (3)
the supreme soul, in which subject and object are no longer distinguished from one
another, or which, according to the Indian conception, is the objectless knowing
- Deussen, Paid, M.D., The Religion and Philosophy of India, pp. 39, 94.
An Oriental writer comments as follows:
"All organic beings have a principle of self-determination, to which the name of
'soul' is generally given. In the strict sense of the word, 'soul' belongs to every being
that has life in it, and the different souls are fundamentally identical in nature. The
differences are due to the physical organizations that obscure and thwart the life of the
soul. The nature of the bodies in which the souls are incorporated accounts for their
various degrees of obscuration.
Each buddhi, with its grasp of senses and the like, is an isolated organism determined
by its past karma, and has its own peculiarly associated ignorance (avidya). The ego is
the psychological unity of that stream of conscious experiencing which constitutes what we
know as the inner life of an empirical self.
The Empirical Self is the mixture of free spirit and mechanism, of purusha and
prakriti... Every ego possesses within the gross material body, which suffers dissolution
at death, a subtle body, formed of the psychical apparatus, including the senses."
- Radhakrishnan, S., Indian Philosophy. Vol. II, pp. 279, 283, 284, 285.
An Indian scripture sums up this teaching as follows: 
there are four Atmas - the life, the mind, the soul, the spirit. The ultimate force which
lies at the root of macrocosmic power of the manifestations of soul, mind, and the
life-principle, is the spirit."
- Prasad, Rama, Nature's Finer Forces, p. 121. (Quoted from the Prashnopanishad.)
therefore, appears to be an expression of the life force, and we begin to approach the
truth as formulated in the East, that matter is spirit or energy in its lowest
manifestation, and spirit is matter in its highest expression. In between these two
extremes, and thus manifesting in time and space, come those diversities of the manifested
life-consciousness which engross the interest of the religious man, the psychologist, the
scientist, and the philosopher, according to their peculiar predilections and tendencies.
All are studying the varying aspect of the one animating life.