Description: The experience of undifferentiated unity is one of the important characteristics of mystical experience. Two aspects of such experience are distinguished, depending upon whether the subject-object dichotomy transcended is between the usual self and some inner world within the experiencer, or whether it is between the usual self and the external world of sense impressions outside the experiencer. Both forms of unity may be experienced successively and it is believed that the states of consciousness ultimately achieved in each case may be identical
[Internal unity]: This is characterized by loss of awareness of all normal sense impressions and the usual sense of individuality, although paradoxically a pure consciousness of what is being experienced remains and seems to expand as a vast inner world is encountered. In the most complete experience, this consciousness is a pure awareness beyond empirical content, with no external or internal distinctions. Although awareness of the empirical ego ceases, the individual does not become unconscious, but rather remains aware of a oneness or undifferentiated unity, associated with a sense of merging with a ground of being.
[External unity]: This is perceived outwardly with the physical senses through the external world. Awareness of one or more particular sense impressions grows in intensity until suddenly the object of perception and the empirical ego simultaneously seem to cease to exist as separate entities, while consciousness seems to transcend subject and object and become impregnated by a profound sense of unity, accompanied by the insight that ultimately all is one. The essences of external objects are experienced intuitively and felt to be the same at the deepest level and that all are a part of the same undifferentiated unity. In the most complete experience, the individual feels in a deep sense that he is a part of everything that exists. Despite this awareness the experiencer retains the knowledge that on another level, at the same time, he and the external objects may be considered separate.