The Origin and Progress of Mankind

Abstract

IN the article under the above title in NATURE of July 21, I am accused by the writer “J. R.” of “ignoring a broad biological principle,” presumably because I was careful not to confuse the principle of “convergent evolution” with wild theories of “spontaneous generation.” Yet in the very next sentence the author of the admonition somewhat inconsequently adds: “The final scientific criterion must be ‘Prove all things.’”