Nature, with longer time to work in, and endless lives to try with,
produce all the varieties of vertebrate animals out of one single common
ancestor? It was a bold idea of the Lichfield doctor--bold, at least,
for the times he lived in--when Sam Johnson was held a mighty sage, and
physical speculation was regarded askance as having in it a dangerous
touch of the devil. But the Darwins were always a bold folk, and had the
courage of their opinions more than most men. So even in Lichfield,
cathedral city as it was, and in the politely somnolent eighteenth
century, Erasmus Darwin ventured to point out the probability that
quadrupeds, birds, reptiles, and men were all mere divergent descendants
of a single similar original form, and even that 'one and the same kind
of living filament is, and has been, the cause of organic life.'

The eighteenth century laughed, of course. It always laughed at all
reformers. It said Dr. Darwin was very clever, but really a most
eccentric man. His 'Temple of Nature,' now, and his 'Botanic Garden,'
were vastly fine and charming poems--those sweet lines, you know, about
poor Eliza!--but his zoological theories were built of course upon a
most absurd and uncertain foundation. In prose, no sensible person could
ever take the doctor seriously. A freak of genius--nothing more; a mere
desire to seem clever and singular. But what a Nemesis the whirligig of
time has brought around with it! By a strange irony of fate, those
admired verses are now almost entirely forgotten; poor Eliza has
survived only as our awful example of artificial pathos; and the
zoological heresies, at which the eighteenth century shrugged its fat
shoulders and dimpled the corners of its ample mouth, have grown to be
the chief cornerstone of all accepted modern zoological science.

In the first year of the present century, Lamarck followed Erasmus
Darwin's lead with an open avowal that in his belief all animals and