Heinrich Zimmer had written exclusively on Hinduism and this is an extract on importance of symbols in Hindu Religion.
The ultimate and real task of philosophy, according to Indian thought transcends the power and the task of reason. Access to truth demands a passage beyond the compass of ordered thought. And by the same token: the teaching of transcendent truth cannot be by logic, but only by pregnant paradox and by symbol and image.
Indian philosophy insists that the sphere of logical thought is far exceeded by that of the mind's possible experiences of reality. To express and communicate knowledge gained in moments of grammar-transcending insight metaphors must be used, similes and allegories.
Indian philosophy, therefore, frankly avails itself of the symbols and images of myth, and is not finally at variance with the patterns and sense of mythological belief.
In the Hindu world, the folklore and popular mythology carry the truths and teachings of the philosophers to the masses. In this symbolic form the ideas do not have to be watered down to be popularized. The vivid, perfectly appropriate pictorial script preserves the doctrines without the slightest damage to their sense.
(Source: Philosophies of India - By Heinrich Zimmer)