For a thousand years after the schools of Athens were closed by Justinian philosophy made no real advance; no essentially new ideas about the constitution of nature, the workings of mind, or the ends of life were put forward. It would be false to say that during this period no progress was made. The civilisation of the Roman Empire was extended far beyond its ancient frontiers; and, although much ground was lost in Asia and Africa, more than the equivalent was gained in Northern Europe.