stantialist thesis endeavours to establish a continuity between one consciousness and another separated by time, by supposing a something durable, of which the consciousness would be a property of intermittent manifestation. They would thus explain the interruptions of consciousness as the interruptions in the light of a lamp. When the light is extinguished, the lamp remains in darkness, but is still capable of being lighted. Let us discard this metaphor, which may lead to illusion. The concept of consciousness can furnish no link and no mental state which remains when the consciousness is not made real; if this link exists, it is in the permanence of the material objects and of the nervous organism which allows the return of analogous conditions of matter.