It would be a distortion to attribute to philosophy in the latter half of the twentieth century any overall unity of philosophical outlook, and I shall, therefore, not try to impose one. Moreover, the closeness to the present of the works in this period makes it even more difficult than usual to discern a prevailing direction in recent philosophy or identify what value posterity will assign to any particular part of it. If one true observation about late-twentieth-century philosophy may be made, it is perhaps only the trite one of its diversity.

To say, however, that there is no discernible overall unity of philosophical outlook – such as realism, or naturalism, or transcendental idealism – in the period under consideration is not to say there were not at different times within it relative concentrations of interest on particular areas in the subject of philosophy, or that there was not for a limited time the stepping to the fore of certain philosophical methods and approaches.

It might be thought that a unity could be granted negatively to at least some of the philosophers considered here through their common rejection of logical positivism, a philosophical movement that had its heyday in the first half of the twentieth century. But this would be a mistake and far too simple. Partly this is because logical positivism is not the pure unfaceted singular doctrine some suppose it to be.