Why Hinduism is known as Santana Dharma? – Sri Aurobindo

Hinduism gave itself no name, because it set itself no sectarian limits; it claimed no universal adhesion, asserted no sole infallible dogma, set up no single narrow path or gate of salvation; it was less a creed or cult than a continuously enlarging tradition of the Godward endeavor of the human spirit.

An immense, many-sided and many staged provision for a spiritual self-building and self-finding, it had some right to speak of itself by the only name it knew, the eternal religion, Sanatana Dharma.

Sri Aurobindo