Dietmar Zaefferer (LMU) gives a talk at the MCMP Colloquium (15 May, 2014) titled "Do Modus Ponens and Tollens Really Leak? Remarks from a Linguistic Semanticist". Abstract: Despite considerable progress in formal logic and semantics conditional constructions continue to be a hotly debated topic. One reason for this difficulty of achieving a consensus could be that the problem is simply too hard to be solvable at the current state of the art, so McGee might still be right with his 1985 conjecture: „It may be that it is not possible to give a satisfactory logic of conditionals. This is not to say that it is not possible to give a linguistic account of how we use conditionals, but only to say that such an account would not give rise to a tractable theory of logical consequence.“ (McGee 1985:471) Another reason could be lack of cross-disciplinary communication: This paper looks at logicians’ discussions of counterexamples to MP an MT from the point of view of a linguist and endeavors to show at least that some of them are fallacious, and at most that a considerable amount of problems in this domain is due to insufficient care in formalization, i.e. in semantic analysis. Assume that the miniature archipelago Twin Islands, consisting of Westland and Eastland, is rarely visited, and that at present Jeff and Jane are the only visitors. Assume further that Jane is on Westland. Then the following propositions seem to be true: (P1) Jeff is not the only visitor. non q; (P2) If Jeff is on Eastland, then Jeff is the only visitor. if p then q. Application of modus tollens should lead us to the truth of: (C1) Jeff is not on Eastland. non p.However, intuitively, this does not seem to follow. So this appears to be a counterexample to modus tollens. But it isn’t. It’s easy to see why: Visitor is a relational noun. Jeff is a visitor can only be the case if there is a location Jeff is a visitor of. Uncovering the hidden parameter makes the counterexample disappear: (P1) Jeff is not the only visitor (of Twin Islands). non q; (P2) If Jeff is on Eastland, then Jeff is the only visitor (of Eastland). if p then r. Since q and r are different, there is no way of applying MT. This seems to be an easy exercise from Semantics 101, but I will argue that recent counterexamples to MT (Yalcin 2012) and MP (Kolodny&MacFarlane 2010) are subject to analogous criticism. If there is time I will also comment on the consequences of these considerations for the restrictor – operator view debate (Gillies 2010). All in all, the direction of impact of these remarks is to argue, pace McGee, that it is not only possible to give a linguistic account of how we use conditionals, but also that such an account could arguably give rise to a tractable theory of logical consequence.

Timothy Bays (Notre Dame) gives a talk at the Workshop on ”Putnam's Model-Theoretic Arguments" (May 23, 2013) titled "Putnam and the Multiverse".

Benjamin Smart (Birmingham) gives a talk at the MCMP Colloquium (10 January, 2013) titled "The Metaphysics of Lazy Worlds". Abstract: Although it is not uncommon for philosophers to put the fundamental laws to one side and discuss, say, causal interactions concerning macroscopic objects like vases, matches and so on (Mumford and Anjum 2011), in this paper we are concerned with our most fundamental physical principles, and the universal laws that can be derived from these. When it comes to predicting ‘evolutions’ of physical systems, there seem to be two mathematically equivalent, but conceptually distinct kinds of what we might call ‘fundamental laws’: there are those laws we, it seems fair to say, are most used to talking about – Newtonian-style laws whereby we can take the state of a system at a time t, apply the relevant laws telling us what will happen next, and correctly predict the state of the system at time t+1. These kinds of law we refer to as ‘equations of motion’. But there is also a fundamental principle of a different nature – a teleological principle telling us that as a physical system evolves from one state to another, the path the system takes through velocity-configuration space is that which minimizes, or to be more precise, extremizes action. This teleological law is conceptually somewhat strange – how does the electron know where it’s going to end up, and what route it should take to take there to minimize the action? Nonetheless it is not a principle to be ignored by the metaphysician, purely because it is strange. We consider, from the viewpoint of four different metaphysical accounts of laws of nature, what this principle of least action (PLA) should be taken to be ontologically, its modal profile, and assuming that laws must have explanatory value, what kind of explanation it affords and where the PLA stands in the explanatory hierarchy.

Manfred Harth (LMU) gives a talk at the MCMP Colloquium (19 June, 2013) titled "Relativism and Superassertibility". Abstract: Relativism about truth is in vogue these days. More and more areas of thought and language are considered as promising candidates for a relativistic semantics in recent years: future contingents, epistemic modals, taste-judgements, knowledge ascriptions, moral judgements etc. However, current truth-relativism is a highly contested position facing some serious problems, and given these problems a look for an alternative shape of relativism seems to be advisable for those of us who are also sceptical about contextualism for the areas in question but have relativistic inclinations all the same. In my talk, I shall explore the prospects of such an alternative for moral judgements, which is based on an epistemic account of truth as stable or superassertibility, i.e. the property of being assertible in some state of information and remaining so no matter what improvements are made to it. The straightforward road to relativism within this framework, which is proposed by Michael Lynch and Crispin Wright, is to admit that two contradictory propositions may be both stably assertible relative to divergent starting points of states of information. Yet, not too surprisingly, this requires a corresponding relativization of the truth predicate – which was to be avoided from the outset. I’ll discuss the following response to this problem: abandoning truth-relativism and limiting relativism to epistemic relativism conjoint with a restriction to intuitionistic logic. I’ll conclude that this response, which I call anti-realist epistemic relativism, may yield a promising approach to relativism in ethics that presents an alternative to truth-relativism and contextualism.

Tobias Rosefeldt (Berlin) gives a talk at the MCMP Colloquium (5 June, 2013) titled "Things that don't exist". Abstract: Are there things that don’t exist? Several answers seem to be possible here. You can answer ‚yes’ because you are a Mainongian and believe that existence is a discriminating property of objects, i.e. a property that some objects have and others lack. You can answer ‚no’ because you are a Quinean and believe that to exist just means to be identical to something and hence is a property of everything. Or you can be a fan of substitutional quantification and think that you can answer ‚yes’ without committing yourself to non-existing things in any ontologically interesting sense. In this paper, I want to introduce an alternative to all these views. According to this alternative, you can answer ‚yes’ to the question but nevertheless assume that (i) ‚exist’ expresses a property true of all objects and (ii) ‚there are things’ expresses objectual quantification. The reason why this is possible is that there is a literal reading of the sentence ‚There are things that don‘t exist’ in which we are using it to quantify over kinds of things and say that there are kinds that have no instances. In order to substantiate this claim, I will show that there are many cases in which natural language quantifiers such as ‚there are things’, ‚there is something’ or ‚there are Fs’ are used to quantify over kinds of things rather than individual things, and give an analysis of the intricate syntactical and semantical features of sentences in which such quantification occurs. I will then use the proposed analysis in order to show that there really is the mentioned reading of the claim that there are things that don’t exist and to explain why it has been overseen by so many philosophers. Finally, I will show how useful the insight into the linguistic structure of our talk about non-existing things is by applying it to several cases in which non-existing things are relevant in philosophy.

Tim Button (Cambridge) gives a talk at the Workshop on ”Putnam's Model-Theoretic Arguments" (May 23, 2013) titled "Naive perception, Cartesian scepticism, and the model-theoretic arguments".

Barbara Vetter (Berlin) gives a talk at the MCMP Colloquium (25 April, 2013) titled "How to be a Dispositionalist about Modality". Abstract: In recent years, metaphysicians have become increasingly attracted to the idea that modality is grounded in, or that modal statements are made true by, the dispositions of concrete objects. Some attempts have been made to formulate the view and to respond to objections. Objections typically come in the form of specific counter-examples to the view. I will raise and answer a different and, I believe, more fundamental kind of objection which has so far been neglected: the objection that dispositionalist views of modality get the logic of modality wrong. Possibilities, for instance, are closed under logical implication; but it is far from obvious that dispositions are too. (A glass, by being disposed to break, need not be disposed to be such that I am sitting or not sitting.) To answer the challenge, the metaphysics and logical behaviour of dispositions needs to be spelled out in much more detail. Answering the objection thus provides us with a deeper understanding of dispositionalism about modality.

Kate Hodesdon (Bristol) gives a talk at the Workshop on ”Putnam's Model-Theoretic Arguments" (May 23, 2013) titled "Internal Realism and Structural Realism".

John Wigglesworth (MCMP/LMU) gives a talk at the MCMP Colloquium (16 July, 2015) titled "Mathematical Structuralism and Metaphysical Dependence". Abstract: The notion of dependence plays various roles in non-eliminative mathematical structuralism. Of particular interest is the dependence relation that is said by some structuralists to hold between an abstract mathematical structure and the various realisations that exemplify that structure. This dependence relation can be used to distinguish between different versions of non-eliminative structuralism. Ante rem structuralists say that the abstract structure is prior to and independent of any realisation of that structure. In re structuralists claim that the realisations are prior, and so the abstract structure is dependent on there being some realisation of that structure. But very little has been said about this notion of dependence. In this talk, I evaluate one account of dependence that can be found in the literature. I then propose an alternative account and use it to assess the dependence claims made by ante rem and in re structuralists.

Johanna Wolff (Hong Kong) gives a talk at the MCMP Colloquium (8 July, 2015) titled "Realism about Measurement and Realism about Magnitudes". Abstract: A realist about measurement, roughly speaking, holds that measurements give us information about, or epistemic access to, the way the world is. Measurement, on such an account, is objective. A realist about magnitudes, understood either as properties or relations, holds that the way measurements provide such objective knowledge is by tracking features of the world, namely certain quantitative properties or relations. Does realism about measurement require realism about magnitudes, or can we be realists about measurement without any additional commitment to magnitudes? Operationalists (Bridgman 1927, Stevens 1935) and nominalists (Field 1980) have traditionally held that it is possible to be a realist about measurement without being a realist about magnitudes. Realism about measurement without realism about magnitudes also seems to be promoted by Representationalism about measurement (Krantz et. al. 1971-90). Against these attempts to divorce realism about measurement from realism about magnitudes, Mundy (1987), Swoyer (1989), and more recently Peacocke (forthcoming) have argued that realism about measurement, while conceptually distinct from realism about magnitudes, nonetheless requires a commitment to magnitudes. My primary question in this paper is how exactly we should understand realism about measurement and realism about magnitudes respectively. A secondary aim will be to see how traditional arguments in favour of realism about magnitudes fare, depending on how we understand these two realisms.