… originally the ego includes everything, later it separates off an external world from itself. Out present ego-feeling is, therefore, only a shrunken residue of a much more inclusive—indeed, an all-embracing—feeling which corresponded to a more intimate bond between the ego and the world about it. If we may assume that there are many people in whose mental life this primary ego-feeling has persisted to a greater or less degree, it would exist in them side by side with the narrower and more sharply demarcated ego-feeling of maturity, like a kind of counterpart to it. In that case, the ideational contents appropriate to it would be precisely of limitlessness and of a bond with the universe—the same ideas with which my friend elucidated the ‘oceanic’ feeling.
Freud, Sigmund. Civilization and Its Discontents. 1st American ed. New York: W. W. Norton, 1962, 15.