A central theme throughout the impressive series of philosophical
books and articles Stephen Toulmin has published since 1948 is the
way in which assertions and opinions concerning all sorts of topics,
brought up in everyday life or in academic research, can be rationally
justified. Is there one universal system of norms, by which all sorts of
arguments in all sorts of fields must be judged, or must each sort of
argument be judged according to its own norms?
‘In The Uses of Argument (1958) Toulmin sets out his views on these
questions for the first time. Reacting severely against the “narrow”
approach to ordinary arguments taken in syllogistic and modern
logic, he advocates—analogous with existing practice in the field of
law—a procedural rather than formal notion of validity. According
to Toulmin, certain constant (“field-invariant”) elements can be discerned
in the way in which argumentation develops, while in every
case there will also be some variable (“field-dependent”) elements
in the way in which it is to be judged. Toulmin’s “broader” approach
aims at creating a more epistemological and empirical logic that takes
both types of elements into account.