at all, through the definite direction given to them by that or some
other intellectual conviction; nor did the sentiments spontaneously
throw up the belief in a God, since in themselves they were equally
capable of gathering round some other object. Though it is true that
men's passions and interests often dictate their opinions, or rather
decide their choice among the two or three forms of opinion, which the
existing condition of human intelligence renders possible, this
disturbing cause is confined to morals, politics, and religion; and it
is the intellectual movement in other regions than these, which is at
the root of all the great changes in human affairs. It was not human
emotions and passions which discovered the motion of the earth, or
detected the evidence of its antiquity; which exploded Scholasticism,
and inaugurated the exploration of nature; which invented printing,
paper, and the mariner's compass. Yet the Reformation, the English and
French revolutions, and still greater moral and social changes yet to
come, are direct consequences of these and similar discoveries. Even
alchemy and astrology were not believed because people thirsted for gold
and were anxious to pry into the future, for these desires are as strong
now as they were then: but because alchemy and astrology were
conceptions natural to a particular stage in the growth of human
knowledge, and consequently determined during that stage the particular
means whereby the passions which always exist, sought their
gratification. To say that men's intellectual beliefs do not determine
their conduct, is like saying that the ship is moved by the steam and
not by the steersman. The steam indeed is the motive power; the
steersman, left to himself, could not advance the vessel a single inch;
yet it is the steersman's will and the steersman's knowledge which
decide in what direction it shall move and whither it shall go.

Examining next what is the natural order of intellectual progress among