The limitations of all these theorists perspectives prompts Callinicos in the second part of the book to outline an alternative approach whose main elements are a critical realist ontology, a Marxist theory of social contradiction, and an egalitarian conception of justice. The main thrust of his argument is to show that Marx's critique of political economy remains inescapable for anyone seeking to challenge the existing world order but only if it maintains an open but rigorous dialogue with other critical perspectives. is, above all, a contribution to this dialogue.