And if we were to ask whether the enemy of the mouse, the _cat_, was known at the same distant time, we should feel justified in saying decidedly, No. The cat is called in Sanskrit mâr_g_âra and vi_d_âla. In Greek and Latin the words usually given as names of the cat, _γαλἑη_ and αιλουρος, _mustella_ and _feles_, did not originally signify the tame cat, but the weasel or marten. The name for the real cat in Greek was κἁττα, in Latin _catus_, and these words have supplied the names for cat in all the Teutonic, Slavonic, and Celtic languages. The animal itself, so far as we know at present, came to Europe from Egypt, where it had been worshipped for centuries and tamed; and as this arrival probably dates from the fourth century A.D., we can well understand that no common name for it could have existed when the Aryan nations separated.[15] In this way a more or less complete picture of the state of civilization, previous to the Aryan Separation, can be and has been reconstructed, like a mosaic put together with the fragments of ancient stones; and I doubt whether, in tracing the history of the human mind, we shall ever reach to a lower stratum than that which is revealed to us by the converging rays of the different Aryan languages. Nor is that all; for even that Proto-Aryan language, as it has been reconstructed from the ruins scattered about in India, Greece, Italy, and Germany, is clearly the result of a long, long process of thought. One shrinks from chronological limitations when looking into such distant periods of life. But if we find Sanskrit as a perfect literary language, totally different from Greek and Latin, 1500 B.C., where can those streams of Sanskrit, Greek, and Latin meet, as we trace them back to their common source? And then, when we have followed these mighty national streams back to their common meeting-point, even then that common language looks like a rock washed down and smoothed for ages by the ebb and flow of thought. We find in that language such a compound, for instance, as _asmi_, I am, Greek ὲσμι. What would other languages give for such a pure concept as _I am_? They may say, _I stand_, or _I live_, or _I grow_, or _I turn_, but it is given to few languages only to be able to say _I am_. To us nothing seems more natural than the auxiliary verb _I am_; but, in reality, no work of art has required greater efforts than this little word _I am_. And all those efforts lie beneath the level of the common Proto-Aryan speech. Many different ways were open, were tried, too, in order to arrive at such a compound as _asmi_, and such a concept as _I am_. But all were given up, and this one alone remained, and was preserved forever in all the languages and all the dialects of the Aryan family. In _as-mi_, _as_ is the root, and in the compound _as-mi_, the predicative root _as_, to be, is predicated of _mi_, I. But no language could ever produce at once so empty, or, if you like, so general a root as _as_, to be.