"For on what basis of probability could one wish to maintain that such beings, of similar nature to each other, could stand in community mediated only by others (corporeal things) of a different constitution, for this latter claim is even more perplexing than the former?"
"The undisputed characteristic of life in what we see by our outer senses is, doubtless, free movement, which shows itself as arising from the will; but the conclusion is not certain that, where this characteristic is not encountered, then no degree of life is found."