5559. Hence is manifest of what nature is the speech of those who are in hell, namely, that, by reason of their foul ideas, it is foul; and that it cannot have conjunction with the speech of the angels; for such ideas as are in hell do not fall into angelic ideas, because they are destructive [thereof]: moreover, that the speech varies there according to the genera and species of the loves; for everyone's love is what thinks and speaks, because the whole spirit, as to interiors and exteriors, is, as it were, his love. The exteriors are their ultimate forms. Hence is manifest what the differences are. The differences are of such a nature that the infernals can scarcely at all understand angelic speech, which, although from ideas in like manner, yet is from such ideas as are opposite to their ideas. But angels can understand the infernals. By this means, also, heaven is separated from the hells.