William Harvey's difficulties (which will be discussed later in this chapter), when trying to change theories that had lasted for millennia, relate to critical realism (CR). Partly because CR challenges very longheld theories, it can be emotionally as well as intellectually challenging. It is not easy for researchers to revise their central beliefs and review how they could have analysed their previous projects differently. There is great interest in CR among students and younger researchers, who have much to gain and less to lose by studying CR. Yet their ‘demand’ for CR teaching and supervision far exceeds the ‘supply’ from senior academics. Absorbing and adapting to CR concepts and rethinking social science require time and effort, and my aim is to help readers to do this as quickly and easily as possible.

As observed in Chapter 1, contradictions between positivists and interpretivists undermine the hope that sociology can be generally respected, convincing and useful in helping to resolve serious global problems of health and illness. This chapter sets out basic CR concepts to show how they help to resolve these problems. The concepts or themes include: the need to separate ontology (being) from epistemology (thinking); the transitive and intransitive; the semiotic triangle; open and closed systems and demi-regs; the possibility of naturalism; natural necessity or the three levels of reality; an example of the three levels in neonatal research; retroduction; power; time sequencing; political economy; the search for generative mechanisms; dichotomies and policy.

Basic critical realist concepts

Need to separate ontology (being) from epistemology (thinking)

Emphasis on visible tangible evidence follows Plato's edict 2,500 years ago that we should not research ‘what is not’ or the seemingly absent or invisible.