Not only must there be a recognized test of existence, if the controversy as to the existence of the Ego is to have any issue, but there must also be a tacit agreement among the disputants as to the meaning of the word Ego. In the absence of such agreement, the discussion can lead to nothing but loss of temper and confusion of thought. And as in the region of metaphysics such agreement is not to be looked for, since, if it existed, the very raison d'etre of metaphysical inquiry would be gone, one can but conclude that to debate such a question as Does the Ego exist?--a question which takes one in an instant to the ultimate limits of human thought--is not merely a mischievous waste of mental energy, but also a proof of mental blindness on the part of those who allow themselves to indulge in so futile a controversy. Even such questions as Does a centaur exist? or Does a mermaid exist? become unanswerable the moment they become metaphysical. For, though neither a centaur nor a mermaid exists, in the sense of being perceptible by man's bodily senses, each of these fabled beings does exist as a creation of the human mind. Is existence, in that sense of the word, equivalent to non-existence? Perhaps it is: but the question goes to the root of human thought; and it is impossible to answer it offhand without begging all the deeper questions which it involves.

As metaphysical controversy was wholly repugnant to Buddha's type of mind, the antecedent

improbability of his having indulged in the most futile of all metaphysical controversies and authoritatively solved the meaningless problem in which that controversy finally centres, is overwhelmingly strong. Moreover, there is, as it happens, positive evidence that, when he was invited to think and teach in the category of the existent and the non-existent, he deliberately refused to do so. The story of the dialogue between Buddha and Vacchagotta will presently be told, and its meaning will be considered. Meanwhile, it is enough for our present purpose to know that, when the wandering monk Vacchagotta challenged the "Exalted One" with the question "Is there the Ego?" and then with the question "Is there not the Ego?" he was in each case answered with silence.