In the remarks which I am about to address to you, my aim is not to contribute any new facts to the clinical history and the pathology of the condition known as aphasia, but to weigh the bearing of the facts already recorded, to examine how far these support the theories that have been based upon them, and to set forth as definitely as may be possible the kind of conclusions warranted by the state of our knowledge. It appears to me that inquiry into this obscure subject has arrived at a stage when little or no further profit can accrue from an aimless accumulation of observations, and that what is now needed is a digestion of the material which lies at hand.