n received his inspiration from the Greek and
Arabian scientists with whom he was familiar. It is interesting that,
following the lines of observation and discovery in a very primitive
way, he let his imagination run on into the future, predicting many
things that have happened already. Thus he says: "Machines for
navigation are possible without rowers, like great ships suited to
river or ocean, going with greater velocity than if they were full of
rowers; likewise {460} wagons may be moved _cum impetu inaestimabili_,
as we deem the chariots of antiquity to have been. And there may be
flying-machines, so made that a man may sit in the middle of the
machine and direct it by some device; and again, machines for raising
great weights."[1]

In continuity with the ideas of Roger Bacon, Francis Bacon (1561-1626)
gave a classification of human learning and laid the real foundation on
which the superstructure of science has been built. Between the two
lives much had been done by Copernicus, who taught that the earth was
not the centre of the universe, and that it revolved on its axis from
west to east. This gave the traditions of fourteen centuries a severe
jolt, and laid the foundation for the development of the heliocentric
system of astronomy. Bacon's classification of all knowledge showed
the relationship of the branches to a comprehensive whole. His
fundamental theory was that nature was controlled and modified by man.
He recognized the influence of natural philosophy, but insisted that
the "history mechanical" was a strong support to it.

His usefulness seems to have been in the presentation of a wide range
of knowledge distinctly connected, the demonstration of the utility of
knowledge, and the suggestion of unsolved problems which should be
investigated by observation and experiment. Without giving his
complete classification of human learning, it may be well to state his
most interesting classification of physical science to show the middle
ground which he occupied between mediaeval thought and our modern
conception of science. This classification is as follows:

1. Celestial phenomena.
2. Atmosphere.
3. Globe.
4. Substance of earth, air, fire, and water.
5. Genera, species, etc.[2]

{461}

Descartes, following Bacon, had much to do with the establishment of
method, although he laid more stress upon deduction than upon
induction. With Bacon he believed that there was need of a better
m