In Jokes and their Relation to the Unconscious (1905) Freud begins by amassing the broadest collection of jokes that he can, in order to determine how many different types of joke there are, their characteristics, and what exactly it is that makes them pleasurable. He discovers various verbal and conceptual techniques. He then distinguishes and investigates jokes with purpose in hostility or obscenity (‘tendentious jokes’), and those without (‘innocent jokes’). In looking at the mechanisms behind jokes Freud concludes that the pleasure arises from an economy in psychical expenditure, in all cases. Freud also notes the similarities of the joke- work with the dream-work and their relations with the unconscious – namely condensation, absurd representations etc., but adds that there are also significant differences. Freud ends by comparing jokes and the comic and humour. He defines and examines the nature and characteristics in the comic and humour. He concludes that whilst all three can be related to an economy in psychical expenditure, they are distinguishable with regards to the intentions behind them, psychical locations and determining conditions.