we can pass over only by building a bridge of words. Some of these
verbal bridges have been decorated with very dignified names, such as
"the luminiferous ether," "gravity," "chemical affinity"; and when we
have shifted from the one side of the chasm to the other we impose upon
the credulity of the public (and even ourselves) by giving out the
impression that these words represent the real objective bridge on which
we crossed.

In how many ways do we by our theories dodge the crucial problem of how
energy is really transmitted, that is, how matter can act on distant
matter across seemingly vacant space. Gravity, and indeed all the forms
of the attractive forces, come under this head. True, we observe certain
regularities in the way in which these phenomena occur, and the
phenomenon at one place seems to be somehow dependent on some exercise
of force at another place. And so we invent an ingenious theory, and
fortify it all around with ponderous algebraic artillery for defense
against all attack. And by persistent use of such theories we hypnotize
ourselves into the belief that we are truly scientific in method, and
are dealing with objective realities, and that these learned theories
are something more than pretentious masks to hide our ignorance of real
nature; when in reality these theories seem to be only a material screen
to shield us from an embarrassing near view of the immediate action of
God in all the various phenomena of the world; for not many find it a
comfortable thought thus to live continuously beneath the great
Taskmaster's eye.

The theory of the luminiferous ether as the medium of the transmission
of light is one of these pretentious bridges of words. Our advancing
knowledge of electro-magnetic phenomena may some day drive us back to a
modified form of the corpuscular theory of light, and then we can throw