The Yoga philosophy has essentially a practical tone and its object consists mainly in demonstrating the means of attaining salvation, oneness, the liberation of the purusha. The metaphysical theory which we have discussed at some length, though it is the basis which justifies its ethical goal, is not itself the principal subject of Yoga discussion, and is only dealt with to the extent that it can aid in demonstrating the ethical view. We must now direct our attention to these ethical theories. Citta or mind always exists in the form of its states which are called vṛttis.[38] These comprehend all the manifold states of consciousness of our phenomenal existence. We cannot distinguish states of consciousness from consciousness itself, for the consciousness is not something separate from its states; it exists in them, passes away with their passing and submerges when they are submerged. It differs from the senses in this, that they represent the functions and faculties, whereas citta stands as the entity containing the conscious states with which we are directly concerned. But the citta which we have thus described as existing only in its states is called the kāryyacitta or citta as effect as distinguished from the kāraṇacitta or citta as cause. These kāraṇacittas or cittas as cause are all-pervading like the ākāśa and are infinite in number, each being connected with each of the numberless purushas or souls (_Chāyāvyākhyā_, IV. 10). The reason assigned for acknowledging such a kāraṇacitta which must be all-pervading, as is evident from the quotation, is that the Yogin may have knowledge of all things at once. Vācaspati says that this citta being essentially of the nature of ahaṃkāra is as all-pervading as the ego itself (IV. 10).