15. (20) Thus far we have offered the considerations appropriate to those asking for demonstration: those whose need is conviction by evidence of the more material order are best met from the abundant records relevant to the subject: there are also the oracles of the Gods ordering the appeasing of wronged souls and the honouring of the dead as still sentient, a practice common to all mankind: and again, not a few souls, once among men, have continued to serve them after quitting the body and by revelations, practically helpful, make clear, as well, that the other souls, too, have not ceased to be.