This sense of weary reiteration is increased by two other doctrines, which are prevalent in Hinduism, though not universal or uncontested. The first of them identifies the human soul with the supreme and only Being. The doctrine of Saṃsâra holds that different forms of existence may be phases of the same soul and thus prepares the way for the doctrine that all forms of existence are the same and all souls parts of, or even identical with the Âtman or Self, the divine soul which not only pervades the world but _is_ the world. Connected with this doctrine is another, namely, that the whole world of phenomena is Mâyâ or illusion. Nothing really exists except the supreme Âtman: all perception of plurality and difference is illusion and error: the reality is unity, identity and rest. The development of these ideas leads to some of the principal systems of philosophy and will claim our attention later. At present I merely give their outlines as indicative of Hindu thought and temperament. The Indian thinks of this world as a circular and unending journey, an ocean without shore, a shadow play without even a plot. He feels more strongly than the European that change is in itself an evil and he finds small satisfaction in action for its own sake. All his higher aspirations bid him extricate himself from this labyrinth of repeated births, this phantasmagoria of fleeting, unsubstantial visions and he has generally the conviction that this can be done by knowledge, for since the whole Saṃsâra is illusion, it collapses and ceases so soon as the soul knows its own real nature and its independence of phenomena. This conviction that the soul in itself is capable of happiness and in order to enjoy needs only the courage to know itself and be itself goes far to correct the apathy which is the great danger of Indian thought. It is also just to point out that from the Upanishads down to the writings of Rabindranath Tagore in the present day Indian literature from time to time enunciates the idea that the whole universe is the manifestation of some exuberant force giving expression to itself in joyous movement. Thus the Taittirîya Upanishad (III. 6) says: "Bliss is Brahman, for from bliss all these beings are born, by bliss when born they live, into bliss they enter at their death."