There are two quite different types of knowledge accessible to human beings. Both are a vital resource for our well-being as humans and both must be respected by any sensible society. The failure to distinguish these types of knowledge results in a certain sort of confusion that is highly dangerous. Type 1 Knowledge – commonly called ‘scientific’, derives from a process of observation, theory and experimentation as applied to the constituents of the world and their interaction. Knowledge grows by carefully defining the conditions of experimental observation such that the same observations can be made by any person at any place and time. Scientific study gives us a way of perceiving reality that has proved enormously powerful. Yet science ‘does something’ to the people who live by it. The method of science demands that the investigators deliberately distance themselves from aspects of their own existence. They need to do work that does not depend on their feelings that day. By contrast, if I want to know what is going on in the social world around me, science can only ever provide a very partial answer, because there is little or no material evidence of what people around me are thinking or feeling. For this we need a different type of knowledge. Type 2 Knowledge, referred to here as ‘narrative’ knowledge is based on our being able to imagine the thoughts, feelings and motivations of others. We use it whenever we need to understand human behaviour, or the behaviour of other animals with complex minds. By means of careful consideration of these two types of knowledge we can understand one of the most important public issues of all time, namely our response to climate change.