Quasi-realism is the meta-ethical view which claims that: Ethical sentences do not express propositions. Instead, ethical sentences project emotional attitudes as though they were real properties. This makes quasi-realism a form of non-cognitivism or expressivism. Quasi-realism stands in opposition to other forms of non-cognitivism (such as emotivism and universal prescriptivism), as well as to all forms of cognitivism (including both moral realism and ethical subjectivism). Overview Simon Blackburn derived quasi-realism from a Humean account of the origin of our moral opinions, adapting Hume's genealogical account in the light of evolutionary game theory. To support his case, Blackburn has issued a challenge, Blackburn's Challenge, to anyone who can explain how two situations can demand different ethical responses without referring to a difference in the situations themselves. Because this challenge is effectively unmeetable, Blackburn argues that there must be a realist component in our notions of ethics. However, argues Blackburn, ethics cannot be entirely realist either, for this would not allow for phenomena such as the gradual development of ethical positions over time. In his 1998 book, Ruling Passions, Blackburn likens ethics to Neurath's boat, which can be changed plank by plank over time, but cannot be refitted all at once for risk of sinking. Similarly, Blackburn's theory can explain the existence of rival ethical theories, for example as a result of differing cultural traditions - his theory allows both to be legitimate, despite their mutual contradictions, without dismissing both views through relativism. Thus, Blackburn's theory of quasi-realism provides a coherent account of ethical pluralism. It also answers John Mackie's concerns, presented in his argument from queerness, about the apparently contradictory nature of ethics. Quasi-realism, a meta-ethical approach, enables ethics based on actions, virtues and consequences to be reconciled. Attempts have been made to derive from it a comprehensive theory of ethics, such as Iain King's quasi-utilitarianism in his book How to Make Good Decisions and Be Right All the Time (2008). Criticisms Despite gaining some of the better qualities of the component theories from which it is derived, quasi-realism also picks up vulnerabilities from these different components. Thus, it is criticised in some of the ways that moral realism is criticised, for example by Fictionalism (see below); it is also attacked along with expressivism and other non-cognitive theories (indeed it has been regarded by some as a sub-category of expressivism). Fictionalism It has been claimed that Blackburn's programme is fictionalist, which