He is showing that science can invent curious and, to the vulgar, incredible things without the aid of magic.

All the inventions which he enumerates have, he declares, been actually made in ancient times, with the exception of a flying-machine (instrumentum volandi quod non vidi nec hominem qui vidisset cognovi, sed sapientem qui hoc artificium excogitavit explere cognosco).
Compare the remarks of S.Vogl, Die Physik Roger Bacos (1906), 98 sqq.] 4.
Thus Friar Bacon's theories of scientific reform, so far from amounting to an anticipation of the idea of Progress, illustrate how impossible it was that this idea could appear in the Middle Ages.

The whole spirit of medieval Christianity excluded it.

The conceptions which were entertained of the working of divine Providence, the belief that the world, surprised like a sleeping household by a thief in the night, might at any moment come to a sudden end, had the same effect as the Greek theories of the nature of change and of recurring cycles of the world.

Or rather, they had a more powerful effect, because they were not reasoned conclusions, but dogmas guaranteed by divine authority.