It is probably of himself that he speaks when he tells us that "the science of optics has not hitherto been lectured on at Paris or elsewhere among the Latins, save twice at Oxford." It was a science on which he had laboured for ten years.

But his teaching seems to have fallen on a barren soil.

From the moment when the Friars settled in the Universities scholasticism absorbed the whole mental energy of the student world.

The temper of the age was against scientific or philosophical studies.

The older enthusiasm for knowledge was dying down; the study of law was the one source of promotion, whether in Church or state; philosophy was discredited, literature in its purer forms became almost extinct.