Another point of comparison lies in the fact that at no time did the
study of man or human nature, from the metaphysical and psychological
point of view, appeal to Darwin as it did to Wallace; and this being so,
the similarity between the impression made on them individually by their
first contact with primitive human beings is of some interest.

Wallace's words have already been quoted; here are Darwin's: "Nothing is
more certain to create astonishment than the first sight in his native
haunt of a barbarian, of man in his lowest and most savage state. One
asks: 'Could our progenitors have been men like these--men whose very
signs and expressions are less intelligible to us than those of the
domesticated animals; men who do not possess the instinct of those
animals, nor yet appear to boast of human reason, or at least of arts
consequent on that reason?' I do not believe it is possible to describe
or paint the difference between a savage and civilised man. It is the
difference between a wild and tame animal."[12]

The last words suggest the seed-thought eventually to be enlarged in
"The Descent of Man," and there is also perhaps a subtle suggestion of
the points in which Wallace differed from Darwin when the time came for
them to discuss this important section of the theory of Evolution. It
needed, however, the further eight years spent by Wallace in the Malay
Archipelago to bring about a much wider knowledge of nature-science
before he was prepared in any way to assume the position of exponent of
theories not seriously thought of previously in the scientific world.

In the autumn of 1853, on the completion of his "Travels on the Amazon
and Rio Negro," Wallace paid his first visit to Switzerland, on a
walking tour in company with his friend George Silk. On his return, and