Thomas Hofweber

Idealism in its strong form is the view that our human minds in particular, not just minds in general, are metaphysically central to reality, somehow. This chapter presents an argument for this strong form of idealism. The argument will come largely from the philosophy of language, which might sound dubious. However, it will be shown that such an argument can establish a substantial metaphysical conclusion nonetheless. One key move is to distinguish two versions of idealism tied to two ways of conceiving of reality: the totality of facts vs. the totality of things. Ontological idealism is false: we are not central for reality understood as the totality of things. However, conceptual idealism, a version of idealism concerning the totality of facts, is true. The argument given in this chapter aims to show why and how that can be.

I argue that the semantic thesis of direct reference and the meta- physical thesis of the supervenience of the non-physical on the physical cannot both be true. The argument first develops a necessary condition for supervenience, a so-called conditional locality requirement, which is then shown to be incompatible with some physical object having object dependent properties, which in turn is required for the thesis of direct reference to be true. We apply this argument to formulate a new argument against the claim that a thisness is analyzable in purely general terms, one that does not rely on complete symmetry nor the falsity of the identity of indiscernibles. I outline a strategy at the end how the conclusion could be avoided, at a price.

Although there is a prima facie strong case for a close connection between the meaning and inferential role of certain expressions, this connection seems seriously threatened by the semantic and logical paradoxes which rely on these inferential roles. Some philosophers have drawn radical conclusions from the paradoxes for the theory of meaning in general, and for which sentences in our language are true. I criticize these overreactions, and instead propose to distinguish two conceptions of inferential role. This distinction is closely tied to two conceptions of deductive logic, and it is the key, I argue, for understanding first the connection between meaning and inferential role, and second what the paradoxes show more generally.

forthcoming in Meanings and other Things: essays on Stephen Schiffer Gary Ostertag (ed.) MIT Press 2007. Schiffer substantially changed his view about propositions and that-clauses somewhere between his two most recent books: Remnants of Meaning and The Things We Mean. I look at what problems his earlier view had, and what reason Schiffer gives for giving it up in favor of his more recent view. I argue that Schiffer’s reasons are not very good reasons, and that instead the problems for Remnants can be solved, contrary to the ones Things faces. I outline how a view in the spirit of the one Schiffer held in Remnants can be formulated and defended against the problems that his version faces. In the end we should go back to a view like the one he held in Remnants.

An under-explored intermediate position between traditional materialism and traditional idealism is the view that although the spatiotemporal world is purely material, minds nonetheless have a metaphysically special place in it. One way this can be is via a special role that subjects have in the metaphysics of material objects. Some metaphysical aspect of material objects might require the existence of subjects. This would support that minds must exist if material objects exist and thus that a mindless material world is impossible. This view, labeled the subjectivity thesis by Anton Friedrich Koch, was defended by him with an intriguing, purely metaphysical argument connected to the individuation of material objects in space and time. The present paper hopes to make progress on assessing the viability of such a position. It starts by critically examining Koch's argument for the subjectivity thesis, as well as similar arguments that give minds a central place in the metaphysics of material objects via considerations about identity and difference. It then compares these ideas to similar ones in the philosophy of time, and concludes with an outlook on whether such a position is viable and what needs to be done to fill the gaps unearthed along the way

In his groundbreaking Grundlagen, Frege (1884) pointed out that number words like ‘four’ occur in ordinary language in two quite different ways and that this gives rise to a philosophical puzzle. On the one hand ‘four’ occurs as an adjective, which is to say that it occurs grammatically in sentences in a position that is commonly occupied by adjectives. Frege’s example was (1) Jupiter has four moons, where the occurrence of ‘four’ seems to be just like that of ‘green’ in (2) Jupiter has green moons. On the other hand, ‘four’ occurs as a singular term, which is to say that it occurs in a position that is commonly occupied by paradigmatic cases of singular terms, like proper names: (3) The number of moons of Jupiter is four. Here ‘four’ seems to be just like ‘Wagner’ in (4) The composer of Tannhäuser is Wagner, and both of these statements seem to be identity statements, ones with which we claim that what two singular terms stand for is identical. But that number words can occur both as singular terms and as adjectives is puzzling. Usually adjectives cannot occur in a position occupied by a singular term, and the other way round, without resulting in ungrammaticality and nonsense. To give just one example, it would be ungrammatical to replace ‘four’ with ‘the number of moons of Jupiter’ in (1): (5) *Jupiter has the number of moons of Jupiter moons. This ungrammaticality results even though ‘four’ and ‘the number of moons of Jupiter’ are both apparently singular terms standing for the same object in (3). So, how can it be that number words can occur both as singular terms and as adjectives, while other adjectives cannot occur as singular terms, and other singular terms cannot occur as adjectives?

It is natural to think that questions in the metaphysics of chance are independent of the mathematical representation of chance in probability theory. After all, chance is a feature of events that comes in degrees and the mathematical representation of chance concerns these degrees but leaves the nature of chance open. The mathematical representation of chance could thus, un-controversially, be taken to be what it is commonly taken to be: a probability measure satisfying Kolmogorov’s axioms. The metaphysical questions about chance seem to be left open by all this. I argue that this is a mistake. The employment of real numbers as measures of chance in standard probability theory brings with it commitments in the metaphysics of (objective) chance that are not only substantial but also mistaken. To measure chance properly we need to employ extensions of the real numbers that contain infinitesimals: positive numbers that are infinitely small. But simply using infinitesimals alone is not enough, as a number of arguments show. Instead we need to put three ideas together: infinitesimals, the non-locality of chance and flexibility in measurement. Only those three together give us a coherent picture of chance and its mathematical representation.

Philosophers and theorists have long been puzzled by humans' ability to talk about things that do not exist, or to talk about things that they think exist but, in fact, do not. _Empty Names, Fiction, and the Puzzles of Non-Existence_ is a collection of 13 new works concerning the semantic and metaphysical issues arising from empty names, non-existence, and the nature of fiction. The contributors include some of the most important researchers working in these fields. Some of the papers develop and defend new positions on these matters, while others offer important new perspectives and criticisms of the existing approaches. The volume contains a comprehensive introductory essay by the editors, which provides a survey of the philosophical issues concerning empty names, the various responses to these issues, and the literature on the subject to date

Ontology is the philosophical discipline that tries to find out what there is: what entities make up reality, what is the stuff the world is made from? Thus, ontology is part of metaphysics, and in fact it seems to be about half of all of metaphysics. It tries to establish what (kinds of) things there are, the other half tries to find out what the (general) properties of these things are and what (general) relations they have to each other. Settling questions in ontology would bring with it major progress in metaphysics. And it would bring with it major progress in a variety of areas in philosophy outside of metaphysics as well. Many philosophical debates outside of metaphysics are quite directly influenced by how things turn out in ontology. Whether or not there are certain entities will give rise to quite different answers in various philosophical debates. I would like to very briefly describe three debates where ontological questions play a central role. These debates are either directly from metaphysics or from other areas of philosophy and they will be of central importance throughout this paper.

Every fifteen years or so Stephen Schiffer writes a state of the art book on the philosophy of language, with special emphasis on belief ascriptions, meaning, and propositions. The latest is his terrific new book The Things we Mean. It is again full of ideas, insights, arguments, expositions, and theories. For us, however, who believe that that-clauses are first and foremost clauses, not referring expressions, and that they thus do not refer to propositions or anything else, The Things we Mean brings home the news that our champion, the author of Remnants of Meaning, has, alas, crossed over to the dark side. Although Schiffer’s earlier book defended one of the best versions of the no-reference theory, and brought up many of the issues that need to be addressed to defend such a theory, he now has recanted and switched sides. His new theory holds that propositions do exist after all, and that-clauses do refer to them. However, some of the motivation for the no-reference theory is incorporated into his new theory. In Remnants of Meaning one of the main reasons for rejecting the reference of that-clauses was the apparent impossibility to compositionally assign that-clauses their referents, and thus to give a compositional semantics for natural language. In The Things we Mean Schiffer still finds fault with any way to compositionally determine what things propositions are. But now the conclusion is not that they are not things, but that they are things that are not reducible to certain other things: they are sui generis entities. But they are not just any kind of sui generis entities, they are pleonastic entities. The use of the term ”pleonastic” might be slightly confusing, though, since propositions according to the new theory are neither pleonastic in the sense of redundant, nor pleonastic in the sense of the pleonastic it, which suggests a no-reference theory. Rather they are pleonastic in a certain technical sense. Simply put, pleonastic entities are the ones that i) can be introduced by 1 something-from-nothing transformations, and ii) the statement that there are such entities doesn’t imply anything about other entities that wasn’t implied before..

One puzzling feature of talk about properties, propositions and natural numbers is that statements that are explicitly about them can be introduced apparently without change of truth conditions from statements that don't mention them at all. Thus it seems that the existence of numbers, properties and propositions can be established`from nothing'. This metaphysical puzzle is tied to a series of syntactic and semantic puzzles about the relationship between ordinary, metaphysically innocent statements and their metaphysically loaded counterparts, statements that explicitly mention numbers, properties and propositions, but nonetheless appear to be equivalent to the former. I argue that the standard solutions to the metaphysical puzzles make a mistaken assumption about the semantics of the loaded counterparts. Instead I propose a solution to the syntactic and semantic puzzles, and argue that this solution also gives us a new solution to the metaphysical puzzle. I argue that instead of containing more semantically singular terms that aim to refer to extra entities, the loaded counterparts are focus constructions. Their syntactic structure is in the service of presenting information with a focus, but not to refer to new entities. This will allow us to spell out Frege's metaphor of content carving.

The relevant alternatives approach in epistemology1 arose some years ago partly out of the hope to be able to reconcile our ordinary claims of knowledge with our inability to answer the skeptic. It was supposed to give rise to an account of knowledge according to which our ordinary claims of knowledge are true, even though the claims about our lack of knowledge that the skeptics make in one of their more persuasive moments are also true. To know, according to such an account, is to have evidence sufficient to rule out all the relevant alternatives. In ordinary life few alternatives are relevant. For example, whether or not we are brains in a vat is not a relevant alternative that we have to be able to rule out. In the debate with the skeptic it may become relevant, and accordingly we might not know something any more then, even though we have the same evidence as in ordinary life. The skeptics cleverly make more and more alternatives relevant, and that is how they succeed. But their success in the philosophy seminar is no threat to our ordinary claims of knowledge, or so the theory goes.

Ontology is the study of what there is, what kinds of things make up reality. Ontology seems to be a very difficult, rather speculative discipline. However, it is trivial to conclude that there are properties, propositions and numbers, starting from only necessarily true or analytic premises. This gives rise to a puzzle about how hard ontological questions are, and relates to a puzzle about how important they are. And it produces the ontologyobjectivity dilemma: either (certain) ontological questions can be trivially answered using only uncontroversial premises, or the uncertainties of ontology are really a threat to the truth of basically everything we say or believe. The main aim of this dissertation is to resolve these puzzles and to shed some light on the discipline of ontology. I defend a view inspired by Carnap’s internal-external distinction about what there is, but one according to which both internal and external questions are fully factual and meaningful. In particular, I argue that the trivial arguments are valid, but they do not answer any ontological questions. Furthermore, I propose an account of the function of our talk about properties, propositions and natural numbers. According to this account our talk about them has no ontological presuppositions for its literal and objective truth. This avoids the ontology-objectivity dilemma, and solves the puzzles about ontology. To do this I look at quantification and noun phrases in general, and at their relation to ontology. I argue that quantifiers are semantically underspecified in a certain respect, and play two different roles in communication. I discuss the relation between syntactic form and information structure, the function of certain non-referential, non-quantificational noun phrases, the uses of bare number determiners, and how arithmetic truths are learned and taught. The more metaphysical issues discussed include: inexpressible properties, logicism about arithmetic, nominalism, Carnap’s view about ontology, the problem of universals, the relationship between ontology and objectivity, different projects within ontology, non-existent....

This paper investigates the connection of intellectual humility to a somewhat neglected form of a limitation of human knowledge—a limitation in which facts or truths we human beings can in principle represent conceptually. I consider some arguments for such a limitation, and argue that, under standard assumptions, the sub-algebra hypothesis is the best hypothesis about how the facts we can represent relate to the ones that we can not. This hypothesis has a consequence for intellectual humility in that it supports it in metaphysics, but not in ordinary inquiry.

The semantics of noun phrases (NPs) is of crucial importance for both philosophy and linguistics. Throughout much of the history of the debate about the semantics of noun phrases there has been an implicit assumption about how they are to be understood. Basically, it is the assumption that NPs come only in two kinds. In this paper we would like to make that assumption explicit and discuss it and its status in the semantics of natural language. We will have a look at how the assumption is to be understood more precisely, what its methodological status should be, whether it has been abandoned in recent work in semantics, and whether it should be abandoned in future work. To do all this, it’s best to start with some historical context.