What are some themes in Stephen Toulmin's writing?

The Importance of Epistemological Context
Toulmin emphasizes the importance of epistemological context. That is, the historical, political, and other factors that shape the way in which we develop and evaluate idea. Toulmin is a harsh critic of modern science, which he argues has sought to abstract scientific knowledge from all context and all questions of morality and political implication, leading to such tragedies as the creation and use of nuclear weapons. Toulmin insists time and again that we cannot ignore the ideas we've inherited, the way in which we've been taught to view certain assumptions as objective reality even though they are specific to our time and place, etc.
Finding a Balance between Absolutism and Relativism
Toulmin is also deeply concerned with questions of absolutism and relativism. As an ethicist, Toulmin was frustrated by what he saw as the overly relativistic approach of anthropologists and others, when they would declare it impossible to pass moral judgement across historical and cultural lines. Toulmin also opposes what he saw as the absolutist tendencies of many analytic philosophers, who ignored their context and expected to find some absolute abstract truth. Toulmin focuses instead on questions of how to approach rhetoric and moral reasoning in a way that is mindful to specific context, without completely sidestepping the the question of how we talk about ethics and morality across historical and cultural lines.
The Key Elements of a Good Argument
Finally, Toulmin was deeply concerned with rhetoric and argumentation. He is perhaps best-known for the six-part Toulmin model of argument, which focuses on making explicit the various elements that go into good argumentation. His attention to the elements of argumentation is based on his philosophy which positions good, grounded argumentation as a key piece of moral reasoning. He emphasizes the importance of focusing less on absolute ideas and more on the way in which people use rational reasoning to evaluate the ideas they have inherited and new ideas they're introduced to.