It seems to me that the Greek mind up to the disaster of the Macedonian Conquest was elaborately and discursively discussing these questions of the forms and methods of thought and that the discussion was abruptly closed and not naturally concluded, summed up hastily as it were, in the career and lecturings of Aristotle.

Since then the world never effectually reopened these questions until the modern period. It went on from Plato and Aristotle just as the art of the seventeenth and eighteenth century went on from Raphael and Michael Angelo. Effectual criticism was absolutely silent until the Renaissance, and then for a time was but a matter of scattered utterances having only the slightest collective effect. In the past half century there has begun a more systematic critical movement in the general mind, a movement analogous to the Pre–Raphaelite movement in art — a Pre–Aristotelian movement, a scepticism about things supposed to be settled for all time, a resumed inquiry into the fundamental laws of thought, a harking back to positions of the older philosophers and particularly to Heraclitus, so far as the surviving fragments of his teaching enable one to understand him, and a new forward movement from that recovered ground.