In the thirty years after 1914, idealist philosophers found themselves divided and uncertain. Many left boxes of unpublished material which record their struggles. Much that remains will prove to be of interest as philosophers return to some of the traditional questions, but much of it is as yet unexplored.

Despite the fact that a concern with language was prominent in the British idealist movement, by the end of this period the movement, along with its realist rival, was eclipsed by a ‘linguistic philosophy’ which was stridently anti-metaphysical in tone. In France the near-idealist philosophie de l'esprit was similarly eased out by existentialism, though Jean Guitton (1939) thought a logical idealist development of Malebranche remained one of the two great philosophical possibilities. In Austria and Germany the idealist tradition continued in the work of the phenomenological movement which flourished alongside the brief flowering of logical positivism; by the end of the period, however, phenomenology itself gave way to Heidegger’s philosophy of being which rejects idealism by affirming the priority of being over thought. Only in Italy did idealism remain the dominant mode of thought, and the conflicting idealist philosophies of Giovanni Gentile and Benedetto Croce were the dominant strands, fascist and liberal, of Italian political thought (idealism also held its own in Canada; see Armour and Trott (1981)).

May Sinclair said (1917: v) that, if you were an idealist philosopher, ‘you [could] not be quite sure whether you [were] putting in an appearance too late or much too early’. Widely circulated arguments had been raised by Bertrand Russell, G. E. Moore, and the American realists against idealism. The idealism they criticised affirmed that mind and its objects form a very close unity, such that the material world cannot be the ultimate reality because its parts are separable and therefore lack the requisite unity. Moore’s counter argument (Moore 1903) was that thinking and perceiving must be separate from their objects.