The Yoga Sutras of Patanjali - A Perspective

There arises the knowledge of the subtle, the veiled, the remote, by directing the light of the higher sense activity towards them

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Concentration on a given object provides knowledge.

Sometimes one observes things casually and half- heartedly. We thus have cursory knowledge of many things, but no real knowledge of any one thing, like a “Jack of all trades, but master of none.”