John Locke's 1689 Two Treatises of Government is a key text in the history of political theory - one whose influence remains marked on modern politics, the American Constitution and beyond. Two Treatises is more than a seminal work on the nature and legitimacy of government. It is also a masterclass in two key critical thinking skills: evaluation and reasoning. Evaluation is all about judging and assessing arguments - asking how relevant, adequate and convincing they are. And, at its heart, the first of Locke's two treatises is pure evaluation: a long and incisive dissection of a treatise...

David Hume's Dialogues Concerning Natural Religion is a philosophical classic that displays a powerful mastery of the critical thinking skills of reasoning and evaluation. Hume's subject, the question of the existence and possible nature of God, was, and still is, a persistent topic of philosophical and theological debate. What makes Hume's text a classic of reasoning, though, is less what he says, than how he says it. As he noted in his preface to the book, the question of 'natural religion' was unanswerable: so 'obscure and uncertain' that 'human reason can reach no fixed determination with...

Thomas Paine's 1776 Common Sense has secured an unshakeable place as one of history's most explosive and revolutionary books. A slim pamphlet published at the beginning of the American Revolution, it was so widely read that it remains the all-time best selling book in US history. An impassioned argument for American independence and for democratic government, Common Sense can claim to have helped change the face of the world more than almost any other book. But Paine's pamphlet is also a masterclass in critical thinking, demonstrating how the reasoned construction of arguments can be...