Definition of Man, also known as the Definition of Human, originated from a summary essay of Kenneth Burke (1897–1993) which he included in his 1966 work, Language as Symbolic Action. Burke's work in communication has spanned many fields and focuses primarily on rhetoric. Perhaps he is best known for his theory of Dramatism, wherein he characterizes life to not just reflect or be like a drama but rather that life is drama.
Burke's definition of man states: "Man is the symbol-using (symbol-making, symbol-misusing) animal, inventor of the negative (or moralized by the negative), separated from his natural condition by instruments of his own making, goaded by the spirit of hierarchy (or moved by the sense of order), and rotten with perfection". Essentially, Burke's definition maintains that man is distinct from other creatures by the virtue of his use of symbols to communicate, his understanding of negation, his separation from nature by his own techniques, his existence in differing social structures, and his goal to become better than he presently is.
Burke distinguishes man from other animals by drawing an analogy between man and birds. He argues that unlike birds, which cannot use symbols to communicate, man is able to use language towards pragmatic ends. To illustrate this point, Burke recalls seeing a bird trapped inside a college classroom. The windows were open, but the bird kept flying upwards to the ceiling, rather than through the window. If the bird could use symbols to communicate then one could simply inform the bird of the open windows and it could fly out to freedom. Its natural instinct to fly up coupled by its inability to use symbols, however, prevents its escape. Burke, also argues that not only does man use symbols, but concedes that man makes and misuses symbols as well.
One aspect of symbols that Burke points out in his discussion of Sigmund Freud's work is condensation. This explains man's ability to condense symbols into categories that can be understood by others to include a variety of other symbols. The example he gives is using the word furniture to refer to chairs, tables, etc.
Burke's defining of man in these terms leads to man's quest for identity and social belonging. Burke sees all human action as infused with symbols. These symbols are used to help create our sense of who we are and where we fit. In order to accomplish these, man seeks for differences and commonalities respectively.