Andrew Sayer 
Realism and Social Science [PDF ebook] 

Realism and Social Science offers the reader an authoritative and compelling guide to critical realism and its implications for social theory and for the practice of social science. It offers an alternative both to approaches which are overly confident about the possibility of a successful social science and those which are defeatist about any possibility of progress in understanding the social world. Written by one of the leading social theorists in the field, it demonstrates the virtues of critical realism for theory and empirical research in social science, and provides a critical engagement with leading non-realist approaches.