He has also attempted to reconcile religion and science, by teaching that the one all-essential belief is in a great unknowable reality, which is not only inscrutable but inconceivable. In writing about this supreme power, he uses capitals with a constancy which would look like an assumption of knowledge, if the same habit were not followed in regard to many other words of much less importance. He admits that "We cannot decide between the alternative suppositions, that phenomena are due to the variously conditioned workings of a single force, and that they are due to the conflict of two forces." "Matter cannot be conceived," he says, "except as manifesting forces of attraction and repulsion"; but he also says that these antagonistic and conflicting forces "must not be taken as realities but as our symbols of the reality," "the forms under which the workings of the unknowable are cognisable." This creed is accepted by many American evolutionists. It is the doctrine of one of Spencer's most elaborate and brilliant interpreters, Professor John Fiske, of such popular clergymen as Doctors Minot J. Savage and Lyman Abbott, and of many of the members of that energetic organisation, "The Brooklyn Ethical Association." _The Open Court_ of Chicago and other periodicals are working avowedly for "the Religion of Science"; but that is not to be established without much closer conformity to the old-fashioned creeds and ceremonies than has been made by Spencer. His later works seem more orthodox than his earlier ones; but his final decision is that "The very notions, origin, cause, and purpose, are relations belonging to human thought, which are probably irrelevant to the ultimate reality." He has also admitted that the proposition, "Evolution is caused by mind," "cannot be rendered into thought." And he is right in saying that he has nowhere suggested worship.