This passage has been cited by the author of a notable work on Sociology[5], and made by him the text of a polemic against the conception of the group mind. He writes: “This passage contains two arguments in favour of the hypothesis of super-individual ‘collective’ minds, neither of which can stand examination. The ‘definition’ of a mind as ‘an organised system of mental or purposive forces’ is totally inadequate. When we speak of the mind of an individual we mean something more than this. The mind of each of us has a unity other than that of such a system.” But I doubt whether Mr Maciver could explain exactly what kind of unity it is that he postulates. Is it the unity of soul substance? I have myself contended at some length that this is a necessary postulate or hypothesis[6], but I do not suppose that Maciver accepts or intends to refer to this conception. Is it the unity of consciousness or of self-consciousness? Then the answer is that this unity is by no means a general and established function of the individual mind; modern studies of the disintegration of personality have shown this to be a questionable assumption, undermined by the many facts of normal and abnormal psychology best resumed under Dr Morton Prince’s term ‘co-consciousness.’ The individual mind is a system of purposive forces, but the system is by no means always a harmonious system; it is but too apt to be the scene of fierce conflicts which sometimes (in the graver psychoneuroses) result in the rupture and disintegration of the system. I do not know how otherwise we are to describe the individual mind than as a system of mental forces; and, until Maciver succeeds in showing in what other sense he conceives it to have “a unity other than that of such a system,” his objection cannot be seriously entertained. He asks, of the alleged collective mind: “Does the system so created think and will and feel and act[7]?” My answer, as set out in the following pages, is that it does all of these things. He asks further: “If a number of minds construct by their interactivity an organisation ‘which can only be described in terms of mind,’ must we ascribe to the construction the very nature of the forces which constructed it?” To this I reply—my point is that the individual minds which enter into the structure of the group mind at any moment of its life do not construct it; rather, as they come to reflective self-consciousness, they find themselves already members of the system, moulded by it, sharing in its activities, influenced by it at every moment in every thought and feeling and action in ways which they can neither fully understand nor escape from, struggle as they may to free themselves from its infinitely subtle and multitudinous forces. And this system, as Maciver himself forcibly insists in another connection, does not consist of relations that exist external to and independently of the things related, namely the minds of