Such a conception finds its strongest support in the analogy afforded by a widely current view of the nature and conditions of the psychical individuality of men and animals; the view, namely, that the individual consciousness of any man or animal is the collective consciousness of the cells of which his body, or his nervous system, is composed. We know that the nervous system is made up of cells each of which is a vital unit, capable of living, of achieving its essential vital processes, independently of other cells; and we see free living cells that in many respects are comparable with these and to which we seem compelled, according to the principle of continuity, to attribute some germ of psychical life however rudimentary. What is known of the phylogenetic and ontogenetic development of the multicellular animal seems to justify us in regarding it as essentially an aggregate of such independent vital units, which, being formed by repeated fission from a single cell, adhere together and undergo differentiation and specialisation of functions. If then the parent cell, the germ cell, has a rudimentary psychical life, it is difficult to deny it altogether to the cells formed from it by fission; and it is argued that all these cells continue to enjoy a psychical life and that the consciousness of the individual man or animal is the collective consciousness of some or all of these cells. Now we know that the consciousness of any one of the higher animals has for its physical correlate at any moment processes going on simultaneously in many different parts and elements of the brain. It is argued, then, that we must suppose each cell of the brain to enjoy, whenever it is active, its own psychical life, and at the same time to contribute something towards the unitary ‘collective consciousness’ of the whole organism, which thus exists beside, but not independently of, these rudimentary consciousnesses of the cells. If the view be accepted, it affords a close analogy with the supposed ‘collective consciousness’ of a group of men or a society.