ABSTRACT
The predominance of evolution over regression was something nineteenth-century anthropologists thought necessary to affirm very forcefully, especially in their writings. Herbert Spencer specifically denied that cultural evolution could best be represented as a unilinear development, saying: "Like other kinds of progress, social progress is not linear but divergent and re-divergent. Hence, in no sense can their evolutionism be described as rectilinear, that is, onward and upward in an unvaryingly straight line. Spencer also pointed to a phenomenon akin to the skipping of stages, namely, the leapfrogging of one culture over another during the process of evolution. Adolf Bastian objected to the ready use of diffusion in explaining instances where a "similarity of ideas was discovered" among primitive peoples. Of all the classical evolutionists, though, none paid more heed to the workings of diffusion than Edward Tylor.
