Existential and functional dependence of consciousness on brain activity, on the body within its surroundings and evolutionary perspective are two fundamental theoretical "touchstones" of the paper. Consciousness is characterized as a quality and capacity of a living organism varying in degrees and types through evolution, fylogeny and ontogeny. Conscious creature is aware of its body and self, it represents the "inner" and "outer" worlds in the form of images, thoughts, feelings, beliefs etc. Evidence for both theses is taken from empirical research on brain-consciousness-behaviour lesions, paleoarcheology, comparative anatomy and morfology, embryology etc. Author considers the coevolutionary research strategy, based on mutual cooperation between humanities and science, of great importance in studying and explaining consciousness, Paper argues towards the possibility of an objective systematic theory of consciousness.