Matter and Memory, p 318 (Fr. p. 267).] Such a theory will not harmonize with the experienced difference between Perceptions and Memories.[Footnote: Le Souvenir du present et la fausse reconnaissance, Revue philosophique, Dec., 1908, p. 568; also L'Energie spirituelle (Mind-Energy).] We do not mistake the perception of a slight sound for the recollection of a loud noise, as has already been remarked. The consciousness of a recollection "never occurs as a weak state which we try to relegate to the past so soon as we become aware of its weakness. How indeed, unless we already possess the representation of a past, previously lived, could we relegate to it the less intense psychical states, when it would be so simple to set them alongside of strong states as a present experience more confused, beside a present experience more distinct?" [Footnote: Matter and Memory, p. 319 (Fr. p. 268).] The truth is that Memory does not consist in a regression from the present into the past, but on the contrary, in a progress from the past to the present. Memory is radically distinct from Perception, in its character. Bergson then passes on to discuss other views of Memory, and in particular, those which deal with the nature of Memory and its relation to the brain. It is stated dogmatically by some that Memory is a function of the brain. Others claim, in opposition to this, that Memory is something other than a function of the brain. Between two such statements as these, compromise or reconciliation is obviously impossible. It is then for experience to decide between these two conflicting views. This empirical appeal Bergson does not shirk. He has made a most comprehensive and intensive study of pathological phenomena relating to the mental malady known as aphasia. This particular type of disorder belongs to a whole class of mental diseases known as amnesia. Now amnesia (in Greek, "forgetfulness") is literally any loss or defect of the Memory. Aphasia (in Greek "absence of speech") is a total or partial loss of the power of speech, either in its spoken or written form. The term covers the loss of the power of expression by spoken words, but is often extended to include both word-deafness, i.e., the misunderstanding of what is said, and word-blindness--the inability to read words. An inability to execute the movements necessary to express oneself, either by gesture, writing, or speech, is styled "motor aphasia," to distinguish it from the inability to understand familiar gestures and written or spoken words, which is known as "sensory-aphasia." The commonest causes of this disease are lesions, affecting the special nerve centres, due to haemorrhage or the development of tumours, being in the one case rapid, in the other a gradual development. Of course any severe excitement, fright or illness, involving a disturbance of the normal circulation in the cerebral centres, may produce asphasia. During the war, it has been one of the