I have attempted in this paper to investigate clinical conditions where aggressive impulses predominate and examine their relation to Freud's theory of the defusion and fusion of the life and death instincts. I have found that even in the most severe states of defusion of the instincts clinical states which resemble Freud's description of the death instinct in its original form reveal on detailed analysis that it is the destructive aspect of the death instinct which is active in paralysing, or psychically killing, the libidinal parts of the self derived from the life instinct. I therefore think that it is not possible to observe an unfused death instinct in the clinical situation.

Some of these destructive states cannot be described as defusions because they are really pathological fusions, in which the psychic structure dominated by a destructive part of the self succeeds in imprisoning and overpowering the libidinal self, which is completely unable to oppose the destructive process.