An explanation of Logos in Greek philosophy is much simpler than is commonly supposed. It is only needful not to forget that for the Greeks thought and word were inseparable, and that the same term, namely, Logos, expressed both, though they distinguished the inner from the outer Logos. It is one of the most remarkable aberrations of the human mind, to imagine that there could be a word without thought or a thought without word. The two are inseparable: one cannot exist or be even conceived without the other. I believe that I have clearly shown in my _Science of Thought_ that thought without word and word without thought are impossible and inconceivable, and why it is so. Here is the first key to a historical solution of the riddle at the beginning of the Fourth Gospel. We know that Greek philosophy after making every possible effort to explain the world mechanically, had already in the school of Anaxagoras reached the view that the hylozoic as well as the atomic theory leaves the human mind unsatisfied; and that it is necessary to posit as the origin of all things a thought or thinking mind that manifests itself in the universe. This was the _nous_, the mind, of Anaxagoras. He could just as well have called it _Logos_, for the word was in use even before the time of Anaxagoras, to express that reason, the recognition of whose all-pervading presence in the universe was the great step in advance made by the system of Anaxagoras. Even Heraclitus had divined the existence of reason in the universe, and had applied to it the name Logos. While the masses recognised in _Moira_ or _Heimarmenê_ only destiny, or fate, Heraclitus declared, that the essence of this Heimarmenê is the _Logos_, the Reason that pervades the world. This is the oldest expression of Hegel’s thought, “What is, is rational.” We must not suppose, however, that Heraclitus considered this Logos as identical with his fire. He merely says that the fire is subordinate to the Logos, that it operates κατὰ τὸν λόγον, according to the Logos, or (as we should say) rationally.