James Strachey's rendering of Freud's term Besetzung, and now a standard term in the psychoanalytic vocabulary of the English-speaking world.
One of the meanings of Besetzung is the occupation of a town or territory.
Like its French equivalent investissement, Besetzung is in common usage, and Freud's choice of terminology reflects his usual reluctance to use a highly technical vocabulary.
Like "libido", "cathexis," and the verb "cathect", coined by Freud's English translator on the basis of a Greek verb meaning "to occupy," have quasi-classical connotations that are not present in the original German.
Freud uses the term to describe the process whereby a quantity of psychical energy becomes attached to an object or idea.
In his earliest writings, Freud describes neurones as being cathected with a quantity of energy or a quota of affect.
There is some variation in usage in the later texts, but the basic notion of quantities of energy remains fairly constant.
Thus, to say that an object is libidinally cathected means that it is charged with sexual energy deriving from sources internal to the psyche.
In Freud's second topography, the id, or the instinctual pole ofthe personality, is said to be the source of all cathexes.