The English word consciousness is used to describe three very different things. The psychologists use it for the contents of mind — thoughts, perceptions, memories. The philosophers use it for the fact of subjectivity — the what-it-is-like quality of experience. The contemplatives use it for the ground of both — the awareness prior to and independent of any particular content.
The yogic tradition has three distinct terms because these are genuinely three distinct realities.
Chitta — the mind-stuff. The psychological dimension of consciousness. The vast, largely unconscious reservoir of all accumulated impressions, memories, conditioned patterns, and the reactive tendencies they generate. Patanjali's Yoga Sutras are primarily about Chitta — its fluctuations, its purification, and the liberation from its compulsive patterns. Most of what we call our inner life is Chitta activity. The thoughts that arise apparently spontaneously, the emotional reactions that seem to have their own volition, the habitual interpretive frameworks through which all experience is filtered — all of this is Chitta.
Chetana — animating awareness, sentient life-force. This is the awareness that inhabits the Chitta, that gives it its living quality. Without Chetana, Chitta would be a dead structure — like a computer without power. Chetana is the living principle, the spark of awareness that makes the mind alive, that allows experience to have a subject. In Samkhya terms, Chetana is Purusha's apparent reflection in Buddhi — the first modification of pure consciousness as it begins to be associated with psychic material.
Chitti — pure Consciousness itself, prior to any psychological content. Kashmir Shaivism's Pratyabhijnahridayam opens with the sutra: Chiti svantantra vishva siddhi hetuh — Chitti, absolutely free, is the cause of the entire universe. This is not the consciousness that is aware of something. This is consciousness as the ground from which all awareness, all content, and all subjects of experience arise. It is self-luminous — not illuminated by anything else because it is the light that makes all illumination possible.
The relationship between the three: Chitti is the ocean. Chetana is the wave — living, moving, the ocean in its dynamic expression. Chitta is the foam on the wave — the surface manifestation, the patterns created by the interaction of the wave with other waves and with the shore. Most psychological work operates at the level of Chitta. Most philosophical inquiry operates at the level of Chetana. The recognition that Abhinavagupta points at is the recognition of Chitti — the ocean recognising that it has always been the ocean and not merely the wave or the foam.
Transcendence of Space-Time: The ordinary mind — Chitta — operates entirely within the framework of space and time. Every thought is located in psychological time (past impressions generating present reactions anticipating future outcomes). Every perception is located in space (this body, here, distinguishable from other bodies, there).
Chetana begins to loosen this framework. In deep meditation, the practitioner discovers that awareness is not produced by a location in space — it simply is, and space appears within it. This is the first hint of the space-time transcendence the traditions describe.
Chitti transcends space and time entirely — not by escaping them but by being recognised as the ground from which they arise. Space and time are modes of perception — ways in which Consciousness structures its own experience. From the level of Chitti, space is the quality of extension that consciousness gives to its own content, and time is the quality of sequence. Both are real at their own level. Both are modes of Chitti rather than independent containers within which Chitti operates.
The practitioner who has recognised Chitti — even partially, even briefly — describes the same thing: a sense of being everywhere and nowhere simultaneously, of the present moment containing all time without being confined to a point within time. This is not mystical language about unusual experience. It is a precise phenomenological description of what consciousness is actually like when it stops misidentifying itself as the Chitta that moves within it.