There is only one state- admittedly an unusual state, but not one that can be stigmatized as pathological- in which it does not do this. At the height of being in love the boundary between ego and object threatens to melt away. Against all the evidence of his senses, a man who is in love declares that 'I' and 'you' are one, and is prepared to behave as if it were a fact.
Sigmund Freud, Civilization and Its Discontents
psychology