Want to know why the coming age will be different from the one that is dying around us? It is because no person and no civilization is large enough to encompass everything; for every truth we accept there is an equally important truth that we reject, and so some things that are true must seem mere superstition to us, and some things that are self-evidently true to us are not, in a larger sense, or seen from another viewpoint, nearly so self-evident, and perhaps not nearly so true.
Lewis Mumford in Interpretations and Forecasts quotes T.E. Hulme as saying, The difference between historical periods is the difference between the categories of their thought.