Possible definitions of critical thinking (1) Critical thinking means not believing everything you read or are being told. (2) Critical thinking means asking people to justify what they say. (3) Critical thinking means asking good questions. (4) Critical thinking means constructing an argument about something. (5) Critical thinking means thinking about how you construct your knowledge of the world. (6) Critical thinking means thinking like a scientist, or historian or mathematician. (7) Critical thinking is philosophy. Problems with these definitions (1) Critical thinking means not believing everything you read or are being told. If we are sceptical about everything we read or are told, then we cannot make any progress in the growth of our knowledge. (2) Critical thinking means asking people to justify what they say. Justification takes different forms and what makes an acceptable justification will vary in different circumstances. (3) Critical thinking means asking good questions. As with justification, what makes a question a ‘good’ question will depend on context, and usually requires knowledge of the thing being looked at. (4) Critical thinking means constructing an argument about something. Arguments can be valid and invalid, and so critical thinking here requires knowledge of how arguments are constructed, both in general and in specific fields. Problems with these definitions (5) Critical thinking means thinking about how you construct your knowledge of the world. It is difficult to get a sense of how your knowledge is being constructed because you often are not conscious of everything affecting your construction of knowledge. (6) Critical thinking means thinking like a scientist, or historian or mathematician. Thinking like a scientist, a historian or a mathematician requires quite in-depth knowledge of those disciplines. (7) Critical thinking is philosophy. There are strict rules about how philosophical questions arguments are constructed that require knowledge of the field of philosophy. Is critical thinking domain-specific? Bailin et al (1999) examined what ‘critical thinking’ means. They argued that critical thinking is not • a skill or set of skills • a mental process • a procedure Instead, they argued that critical thinking involves the application of context-specific and domain-specific reasoning. They went on to argue that the following kinds of knowledge are needed in order to enter into a process of critical thinking: • knowledge of the background of the thing we are thinking about • knowledge of what ‘good thinking’ about that something looks like • knowledge of critical concepts such a ‘evidence’ and ‘proof’ Can you prove • that the area of a circle is πr2? • that water contains hydrogen? • that the earth has moving tectonic plates? • that perestroika led to the collapse of the Soviet Union? • that Abai wanted Kazakhstan to look to the west? How would you go about proving these points? What kind of critical thinking would it require? What questions would you ask of this source? What is being shown in this source? Why was this source produced? Subject Chemistry History Geography Literature What does critical thinking look like in this subject? What kinds of activities can teachers do to get pupils thinking critically in this subject?