One of the legendary Chinese sage-poets, Han Shan, is said to have carried a scroll on which was written—nothing at all. Empty of thoughts of the world, and free from the prison of thinking about himself, his mind was filled with the light which has its source in the true Self. A similar teaching is found in all spiritual traditions, from Christ's injunction to 'take no thought for the morrow', to the Taoist saying: 'Emptiness does not fail to illumine, and illumination does not fail to empty.'

In his Masnawi, Rumi tells of a Sufi who found a food wallet—that was empty. He danced for joy. Soon, other Sufis caught on, and danced with him. A bemused onlooker asked, disparagingly: 'What's the matter? Only a food-wallet hung on a nail, and it is empty of bread!' But for the dancing Sufis, the emptiness was a reminder of that self-forgetfulness where the inner 'vacuum' is instantaneously filled with the divine consciousness. In the words of Shri Dada: 'Know that happiness depends on two factors—forgetfulness of narrow egoity, and illumination of the vacuity in the mind caused thereby!'

Dr Shastri used to relate a well-known Zen story often enough to suggest that its message needs to be learnt and re-learnt, as our self-knowledge deepens.

There was in Japan a Zen monk who was an adept in meditation. Among the men from all walks of life who were attracted by his reputation as a teacher, was a well-known Professor of the Imperial University of Tokyo. The Professor went to see the monk, who offered him the customary green tea. Placing a cup before the distinguished visitor, he poured tea into it until it became full. He continued to pour, and the cup overflowed. Seeing the tea spilling over the table and on to the floor-mats, the startled Professor asked for an explanation. The Zen monk said: 'I can fill what is empty, but not that which is already full. You have come to me with your mind full of ideas of meum and tuum, ambitions and desires. If you seek my instruction, empty your mind, forget all you have learnt, and rid yourself of all harmful and useless matter; then return and I will teach you.'