St. Gregory of Nyssa speaking to St. Macrina, Sister of St. Basil: "Clearly, replied the Teacher, you have not quite attended to the argument. In speaking of the soul's migration from the seen to the unseen, I thought I had omitted nothing as regards the question about Hades. It seems to me that, whether in the heathen or in the Divine writings, this word for a place in which souls are said to be means nothing else but a transition to that Unseen world of which we have no glimpse.
And how, then, I asked, is it that some think that by the underworld is meant an actual place, and that it harbours within itself the souls that have at last flitted away from human life, drawing them towards itself as the right receptacle for such natures?
Well, replied the Teacher, our doctrine will be in no ways injured by such a supposition. For if it is true, what you say , and also that the vault of heaven prolongs itself so uninterruptedly that it encircles all things with itself, and that the earth and its surroundings are poised in the middle, and that the motion of all the revolving bodies is round this fixed and solid centre, then, I say, there is an absolute necessity that, whatever may happen to each one of the atoms on the upper side of the earth, the same will happen on the opposite side, seeing that one single substance encompasses its entire bulk. As, when the sun shines above the earth, the shadow is spread over its lower part, because its spherical shape makes it impossible for it to be clasped all round at one and the same time by the rays, and necessarily, on whatever side the sun's rays may fall on some particular point of the globe, if we follow a straight diameter, we shall find shadow upon the opposite point, and so, continuously, at the opposite end of the direct line of the rays shadow moves round that globe, keeping pace with the sun, so that equally in their turn both the upper half and the under half of the earth are in light and darkness; so, by this analogy, we have reason to be certain that, whatever in our hemisphere is observed to befall the atoms, the same will befall them in that other. The environment of the atoms being one and the same on every side of the earth, I deem it right neither to contradict nor yet to favour those who raise the objection that we must regard either this or the lower region as assigned to the souls released. As long as this objection does not shake our central doctrine of the existence of those souls after the life in the flesh, there need be no controversy about the whereabouts to our mind, holding as we do that place is a property of body only, and that soul, being immaterial, is by no necessity of its nature detained in any place."