I start from the position that no doctrine can receive a general acceptation among men which does not depend on a truth of nature. The various religions agree on one point, and this is the doctrine of the immortal soul. Such a point of universal agreement, I am convinced, cannot have been entirely derived from the air. It must have had some foundation in fact, and the question arises, What was this foundation? Dreams and phantasms, as Spencer believes? No; there must have been something real and genuine, and the path we have entered upon to find traces of this true foundation of the conception of the soul cannot be distrusted. We must compare the conception of the soul as held by various related religions, and strip off from it all those attributes which are not common to all. But those which all the various religions agree in ascribing to the soul we may regard as its true attributes. It would take too long to go into the details of this examination of the conception of the soul. As the general result of a comparison of the various views of the soul we may put down the following characteristics which are invariably ascribed to it: (1) The soul is living. (2) It survives the body, and can continue to exist without it. (3) During life it is contained in the body, but leaves it after death. (4) The soul participates in the conduct of the body: after the death of the latter, causality (retribution) can still affect the soul. The characteristics (1) to (3) hold also for the series of reproductive cells continually developing within the body; and these attributes of the germ cells may well be the true but unrecognized cause of the origin of those conceptions of the soul's character. This like holds true for (4), although the connection is not so obvious. For this reason it will be advisable to consider the point in more detail. It has been already indicated that the founders of religions have made use of the survival of the soul after death to endeavor to lead mankind to live righteously, by threats of punishments or promises of reward, which will affect the soul after the death of the body. It is precisely on this point that in the most highly developed religions there is the greatest falling off from the original conception of the after-effect of human conduct on the soul, and the most astounding things are inculcated by the Koran and other works with respect to this. But here again we may separate the true kernel from the artificial shell, and reach the conclusion that good conduct is advantageous for the soul after the death of the body, and that bad conduct is detrimental. In no other way can the Mohammedan paradise or the Christian hell be explained than as sheer anthropomorphic realizations of these facts, which can appeal even to the densest intellect. What then is good conduct, or bad?