https://archive.org/details/mappinghypertext0000horn/page/210/mode/2up

The British philosopher Stephen Toulmin and the Belgians, Chaim Perelman and L. Olbrechts-Tyeca have claimed that the reasoning process involved in most discussions about policy, ethics, law, and business strategy is more complex than the three part structure of the classic syllogism (i.e., major premise, minor premise, conclusion). They have suggested a way of capturing the subtleties and overall structure of reasoning processes. In this chapter we focus on the approach of Toulmin.