ork on the thing; Science had begun,
and the first triumph of it was the power of foretelling the future.
Eclipses were perceived to recur in cycles of nineteen years, and
philosophers were able to say when an eclipse was to be looked for. The
periods of the planets were determined. Theories were invented to
account for their eccentricities; and, false as those theories might be,
the position of the planets could be calculated with moderate certainty
by them. The very first result of the science, in its most imperfect
stage, was a power of foresight; and this was possible before any one
true astronomical law had been discovered.

We should not therefore question the possibility of a science of
history, because the explanations of its phenomena were rudimentary or
imperfect: that they might be, and might long continue to be, and yet
enough might be done to show that there was such a thing, and that it
was not entirely without use. But how was it that in those rude days,
with small knowledge of mathematics, and with no better instruments than
flat walls and dial plates, those first astronomers made progress so
considerable? Because, I suppose, the phenomena which they were
observing recurred, for the most part, within moderate intervals; so
that they could collect large experience within the compass of their
natural lives: because days and months and years were measurable
periods, and within them the more simple phenomena perpetually repeated
themselves.

But how would it have been if, instead of turning on its axis once in
twenty-four hours, the earth had taken a year about it; if the year had
been nearly four hundred years; if man's life had been no longer than it
is, and for the initial steps of astronomy there had been nothing to
depend upon except observations recorded in history? How many ages would
have passed, had this been our condition, before it would have occurred
to any one, that, in what they saw night after night, there was any kind
of order at all?

We can see to some extent how it would have been, by the present state
of those parts of the science which in fact depend on remote recorded
observations. The movements of the comets are still extremely uncertain.
The times of their return can be calculated only with the greatest
vagueness.

And yet such a hypothesis as I have suggested would but inadequately
express the position in which we are in fact placed towards history.
There the phenomena never rep