Hinduism is a living organism. One and indivisible at the root, it has grown into a vast tree with innumerable branches. Knowledge is limitless and so also the application of truth. Everyday we add to our knowledge of the power of Atman (soul) and we shall keep on doing so.
A principle is the expression of perfection, and as imperfect beings like us cannot practise perfection, we devise every moment limits of its compromise in practice.