Because so much of Freud’s argument regarding the traumatic neuroses rests on the idea of a disruption of the pleasure principle by excessive excitations, this chapter explores this concept in some detail. The first part focuses on Freud’s basic theory and especially the inherent contradiction within it between the idea of a ‘tendency towards zero’ and that of a ‘homeostasis’ of psychical energy. It utilises Laplanche’s arguments on this topic to highlight the key problems. The latter part of the chapter discusses Lacan’s approach to the pleasure principle, which marks a shift from a theory of energetics to one of cybernetics. The focus is on Lacan’s arguments in Seminar II where he utilises cybernetic theory to explore how language, especially in the form of a ‘binary code’, can act both as a self-regulating system whilst at the same time having a disruptive and somewhat paradoxical ‘creative-destructive’ effect on the human subject. This part of the chapter also included a discussion, drawing especially upon the work of Lydia Liu, regarding the influence of ‘French Theory’ on Lacan’s work and how this has shifted the emphasis away from the important legacy of cybernetics and information theory in Lacan’s work.