Did Wallace really believe that Earth was located at the center of the Universe, and that our planet was the only one that hosted living things?
Yes, and no–that is, yes, he believed Earth is located at or near the center of the Universe (though his exact opinions on this matter changed as time went on), but no, he did not argue that we were necessarily the only place in the cosmos where life existed. In Wallace’s time the Universe was not definitely known to extend beyond our own galaxy. Wallace used a variety of contemporary sources of astronomical data to come to the conclusion that our Sun is located at the center of the Milky Way–an incorrect conclusion, of course–and that it was highly unlikely that any other planet existed which harbored advanced life forms. He has frequently been misunderstood on this latter point; most sources refer to him as not believing in the likelihood of any kind of life existing anywhere else. However, he himself once stated: “I need hardly say, I suppose, that I have never suggested that this earth alone in the whole universe is the abode of life. What I do say is . . . that all the availabl
