In this paper, perhaps the first of its kind, an attempt is made to elucidate and examine the Vedantic theory of soul constructed on the basis of the experience of dreamless sleep which, being radically and qualitatively different from waking and dreaming states, is considered by the Vedantins as a state of temporarily purified individual soul (atman), a state of pure substantial consciousness. They take the experience of dreamless sleep as a model experience of the soul's final liberation from the (...) body and its internal as well as external faculties. The ultimate liberation, according to the Vedantins, is a state of total identification of the individual soul with the Universal Soul (Brahman), the summum bonum of every Vedantin. The paper also includes a critique of the Vedantic soul theory by the Buddhists who vehemently deny any autonomous and substantial soul whose essence is unchangingly permanent, pure consciousness and self-illuminating knowledge. The soul is instead interpreted by the Buddhists as a product of the functioning of a person's psycho-physical organism and a mere subject of knowing, thinking, desiring, etc. The analysis further shows that the Vedanta, especially the Advaita Vedanta, metaphysics of soul is inadequate in many respects and mainly based on a priori and scriptural arguments and emotive appeals, whereas the Buddhists deny any kind of autonomous and permanent agent of knowing, thinking and desiring by successfully reducing substantial consciousness to mere acts of knowing. (shrink)