A careful consideration of the phenomena of sadism and masochism may be said to lead us to the conclusion that there is no real line of demarcation. Even De Sade himself was not a pure sadist, as Bloch's careful definition is alone sufficient to indicate; it might even be argued that De Sade was really a masochist; the investigation of histories of sadism and masochism, even those given by Krafft-Ebing (as, indeed, Colin Scott and Féré have already pointed out), constantly reveals traces of both groups of phenomena in the same individual. They cannot, therefore, be regarded as opposed manifestations. This has been felt by some writers, who have, in consequence, proposed other names more clearly indicating the relationship of the phenomena. Féré speaks of sexual algophily[98]; he only applies the term to masochism; it might equally well be applied to sadism. Schrenck-Notzing, to cover both sadism and masochism, has invented the term algolagnia (algos, pain, and lagnos sexually excited), and calls the former active, the latter passive, algolagnia.[99] Eulenburg has also emphasized the close connection between these groups of perverted sexual manifestations, and has adopted the same terms, adding the further group of ideal (illusionary) algolagnia, to cover the cases in which the mere autosuggestive representation of pain, inflicted or suffered, suffices to give sexual gratification.[100] A brief discussion of the terms "sadism" and "masochism" has imposed itself upon us at this point because as soon as, in any study of the relationship between love and pain, we pass over the limits of normal manifestations into a region which is more or less abnormal, these two conceptions are always brought before us, and it was necessary to show on what grounds they are here rejected as the pivots on which the discussion ought to turn. We may accept them as useful terms to indicate two groups of clinical phenomena; but we cannot regard them as of any real scientific value. Having reached this result, we may continue our consideration of the love-bite, as the normal manifestation of the connection between love and pain which most naturally leads us across the frontier of the abnormal.