Metaethics is one of the important branches of ethics (along with normative and applied ethics) and it explores the nature of ethical properties, attitudes, and judgments. In metaethics, expressivism constitutes a theory on the meaning of moral language. According to expressivism, sentences in which moral terminology is used are not descriptive or fact-stating; moral terms such as ‘good’ or ‘bad’ do not refer to real or existing properties (in contrast to, for instance, 'red'), but are used to express attitudes (such as approval or disapproval). 

Frege-Geach

In their paper, philosophers Incurvati and Schlöder develop a novel solution to the negation version of the Frege-Geach problem. In the original version, this problem revolves around the fact that simple sentences that express moral judgments (such as ‘It is wrong to tell lies’) can be part of semantically complex sentences (such as ‘If it is wrong to tell lies, then it is also wrong to get your little brother to tell lies’) in a way that expressivists cannot easily explain.

Recently, the debate has focused more on the negation version of the problem. Here, the difference between normative and descriptive negations comes to the fore. Normative claims (such as ‘Murdering is wrong’ vs ‘Murdering is not wrong’), if receiving expressivist treatment, must be read as expressing different attitudes towards the same content. Thus, it seems that not here modifies attitudes. However, in descriptive claims (‘Murdering is legal vs Murdering is not legal’), the term not modifies the content of what is claimed.

Incurvati and Schlöder present a solution to this problem by developing a version of expressivism called inferential expressivism – a novel semantic framework that characterises meanings by inferential roles that define which attitudes one can infer from the use of terms. The UvA philosophers are the first to systematically apply expressivism and inferentialism to normative vocabulary.