It is not unreasonable to try to discover why St John chose the Greek word ‘logos’ in describing the second person of the blessed Trinity to Greek-speaking converts. The only way to discover why is to see just what meaning it had in current speech to induce him to consider it suitable for his purpose; and to see secondly what modification or modifications he had to introduce into its meaning so that it really would fulfil its function as a key word in Trinitarian doctrine. We may find that its chief virtue was that it was, of all the terms to hand, least likely to be misunderstood.

The word ‘logos’ was used by Plato, the Stoics, Philo and Plutarch. It was current coinage in Greek thought, one of those words whose meaning was fluid enough, somewhat as democracy or liberty are in our politically-minded age. But at the back of all these interpretations or uses and shades of meaning of ‘logos', there still remained one which may be summed up in another: reason.