The field of mental effort is not measurable, and so far as
we know, is unlimited. To fix its bounds would be to set an
arbitrary limit to the progress of the human race. In science,
art, literature--in all that exalts and embellishes life--the
space yet available for progress comes as near infinitude as
anything we are capable of conceiving. To one who stands in
a valley, the horizon is near; let him climb a hill, and his
view is expanded. When he attains a greater height the prospect
appears still wider. The inventive genius of the world is
rising higher and higher every day. Its prospect never appeared
so utterly boundless as now. All that has been achieved, all
the grand conquests that are recorded, are but an atom in the
balance weighed when brought against the possibilities of the
future.--_The Inventive Age._
(1180)