Bart Streumer

Berkeley defends idealism partly by taking ordinary objects such as tables and stones to consist of ideas. Materialists reject this account of ordinary objects. I argue that Berkeley can undermine this rejection by making quasi-realist moves of the kind that many expressivists about normativity make. This ultimately results in a version of idealism that we cannot believe, since trying to believe it will make us believe materialism. But I argue that this version of idealism may nevertheless be true.

This paper presents a new argument for robust realism, the view about normativity that Philip Stratton‐Lake held. The argument has three main premises: that we cannot believe an error theory about all normative judgements; that trying to endorse the best version of expressivism makes us believe robust realism; and that trying to endorse the best version of reductive realism also makes us believe robust realism. I argue that combining these premises with some additional premises yields a transcendental argument for robust realism.

Consequentialists often argue that their opponents’ views can be consequentialized or that their own view is partly self-effacing. These arguments resemble the quasi-realist moves that many expressivists make. I argue, however, that consequentializing and self-effacement are surprisingly hard to accommodate within an expressivist framework. This threatens to show that expressivism is false, since it threatens to show that there are meaningful normative sentences that do not express noncognitive attitudes. I then argue that this threat can be neutralized by taking expressivists’ quasi-realist moves further than they are normally taken. This also reveals a deeper resemblance between quasi-realist moves and self-effacement.

This paper defends Frank Jackson’s argument against irreducibly normative properties from attacks by Jonathan Dancy and other non-naturalist moral realists. Jackson argues that since normative properties supervene on descriptive properties, every normative property is identical to a descriptive property. The paper discusses four objections to this argument: that the disjunctive predicate on which the argument relies cannot be formulated; that necessarily coextensive predicates do not always ascribe the same property; that the argument can be refuted by appealing to Leibniz’ Law; and that irreducibly normative properties are indispensible to deliberation. The paper argues that all of these objections fail. In doing so, it also offers two new versions of the argument. It ends by discussing three reasons why Dancy and other non-naturalists may remain unmoved.

Quasi‐realists are expressivists who say much of what realists say. To avoid making their view indistinguishable from realism, however, they usually stop short of saying everything realists say. Many realists therefore think that something important is missing from quasi‐realism. I argue that quasi‐realists can undermine this thought by defending a version of quasi‐realism that I call super‐quasi‐realism. This version seems indistinguishable from realism, but I argue that this is a mistaken impression that arises because we cannot believe super‐quasi‐realism.

There is a well‐known argument against irreducibly normative properties that appeals to the following claim about supervenience: for all possible worlds W and W*, if the instantiation of descriptive properties in W and W* is exactly the same, then the instantiation of normative properties in W and W* is also exactly the same. This claim used to be uncontroversial, but recently several philosophers have challenged it. Do these challenges undermine this argument? I argue that they do not, since the negation of this claim about supervenience has consequences that are much more implausible than the negations of key premises in these challenges.

We argued that formal objections to the error theory overgeneralize and therefore fail. Christine Tiefensee and Gregory Wheeler deny this. We argue that they are wrong, for two reasons. The first concerns how we should adjudicate conflicts between formal and substantive commitments. The second concerns an overlooked tension between formal objections and non-error-theoretic views. Our discussion shows that the commitments behind formal objections to the error theory, such as the dual schema, should be regarded as much more contentious than is often assumed.

Unbelievable Errors defends an error theory about all normative judgements: not just moral judgements, but also judgements about reasons for action, judgements about reasons for belief, and instrumental normative judgements. This theory states that normative judgements are beliefs that ascribe normative properties, but that normative properties do not exist. It therefore entails that all normative judgements are false. Bart Streumer also argues, however, that we cannot believe this error theory. This may seem to be a problem for the theory. But he argues that it makes this error theory more likely to be true, since it undermines objections to the theory and it makes it harder to reject the arguments for the theory. He then sketches how certain other philosophical theories can be defended in a similar way. He concludes that to make philosophical progress, we need to make a sharp distinction between a theory's truth and our ability to believe it.

It is sometimes suggested that there are two kinds of reasoning: inferential reasoning and non-inferential reasoning. However, it is not entirely clear what the difference between these two kinds of reasoning is. In this paper, I try to answer the question what this difference is. I first discuss three answers to this question that I argue are unsatisfactory. I then give a different answer to this question, and I argue that this answer is satisfactory. I end by showing that this answer can help to resolve some disagreements in which the difference between inferential and noninferential reasoning plays a role.