Research

Current Project

Project Abstract (Projektnummer 517008210) (joint project with Matteo Pascucci)

Combining modal notions (such as 'necessary', 'possible', etc.) and quantification in a formal setting is known to be a particularly challenging task. In the present project we will contribute to this task via the Quantified Argument Calculus (Quarc), a recent logical framework,  which aims at providing a more faithful formal representation of the syntactical and semantic structure of natural language sentences than the one offered by the language of the Predicate Calculus (PC).

The project has two main objectives: 

Obj1 developing a correspondence theory for modal extensions of  Quarc; 

Obj2 using the outcomes of (Obj1) to address  foundational problems in quantified modal logic. 

These two objectives give rise to four research questions (Q1-Q2 related to Obj1,  Q3-Q4 related to Obj2): 

    Q1 which fragments of  Quarc can be axiomatized? 

    Q2 which interactions between quantification and modalities can be captured in Quarc? 

    Q3 what is the relationship of modal logics and natural language?

    Q4 what metaphysical impact does the choice of a modal logic have?

The methods employed within the project are interdisciplinary, taken from analytic philosophy and logic. From the philosophical point of view, we will use methods such as conceptual analysis,  disambiguation of natural language sentences, taxonomies and ontological assessment.  From the logical point of view, we will use methods for deductive reasoning, such as axiomatic methods, formal definitions, semantic inference, metalogical theorems and correspondence results.

The project will provide a novel and original perspective on quantified modal reasoning, since Quarc is a very recent framework whose technical foundation and philosophical applications still need to be explored to a considerable degree. In many regards, Quarc has the potential to better deal with certain traditional problems affecting first-order modal logic.

Previous Project

Project Description (GOIPD/2022/635)

Explication, Tolerance, and Pluralism

Summary

Quite generally, the proposed research investigates the relationship between language and reality. We often take reality to be reflected in our language. For example, we express that there is a table by simply saying 'there is a table'. However, we also know that this simple picture cannot be upheld. For example, we do not take the utterance of 'there is a ghost' to reflect that there are ghosts, even if the person who utters the sentences is convinced of its truth. Similarly, there are many constructions in natural languages which do not correspond to reality. One example is the construction of 'for the sake of'. Even though we can do things for the sake of something, there are no such things as sake. One common strategy in ontology to deal with this is to provide paraphrases. A paraphrase of a sentence is another sentence which says the same, but uses different words and constructions. For example, we can paraphrase a sentence such as 'there is a chance of rain' with the sentence 'it likely rains'. The first sentence seems to say that there are chances; yet, the second one does not. Given that both sentences express the same facts, it becomes clear that at least one of these two sentences cannot straightforwardly reflect reality. However, for any given sentence, there can be many paraphrases, and it seems arbitrary to suggest that one reflects reality and not the paraphrased sentence. Thus, if we allow paraphrases - and I argue that we should - we are driven towards a pluralistic position: we need to accept many paraphrases. This, though, seems to conflict with the position that what exists does not depend on any given language. The project investigates how these two positions can be meshed with one another.

The Project

The general aim of my proposed research is to study different forms of pluralism and to investigate what metaphysical impact such pluralism has. In particular, my project investigates whether certain forms of pluralism can be combined with a robust realist metaphysical outlook. In the following, I'll concentrate on a form of language pluralism, i.e., the position that many different languages can be adequate. This proposal brings together debates which have, so far, been separated. On the one hand, the overarching area is metametaphysics, but we also draw heavily on the philosophy of logic and philosophy of science.

The first objective of the research is to argue for the language-pluralist position, i.e., the position that we should be tolerant with respect to languages. It is at odds with many contemporary approaches to metaphysics which rely on arguments that there is one best language in which we should do metaphysics.

(Q1) What are the arguments for language pluralism.

We can approach this question from two directions. Firstly, we can propose arguments that establish the language pluralism. Secondly, we can propose arguments which show that language monism - the position that there is one best language - is flawed. Let me concentrate on the first direction establishing language pluralism. There are several ways to arrive at this conclusion. One simple one is the fact that we do speak different languages which are all, on the whole, equally good; it does not matter whether we use English or German. However, it is not entirely clear that this gets to an interesting form of language pluralism.

A different way to establish the thesis is to look at paraphrases. Paraphrases are prevalent in the philosophical literature. However, as I argue in my PhD thesis, they are poorly understood. In particular, I argue that we need criteria for adequate paraphrase. However, I also show that the common candidate criteria are unsatisfactory. In particular, we need to account for the availability of several such paraphrases. These, then, lead to a form of language pluralism. For, the paraphrases can very well conflict with one another, and to make sense of them, I argue that we'd better understand them as given in different languages. Thus, there is a way from paraphrase to this form of pluralism.

However, this form of language pluralism comes with its own problems. In particular, we need a way to formulate a coherent position.

(Q2) Can we formulate a coherent form of language pluralism.

One problem is that we have to presuppose a particular language to formulate such a position - but that language might already conflict with the formulation. But if we cannot formulate such a position, do we need to dismiss it? It might just be an artifact of each particular language to be incapable to formulate the more general position, without the position becoming incoherent. This needs to be further investigated.

We also face a problem that the language monist does not face. A language monist can uphold a robust metaphysical realism, i.e., the position that what reality is like does not depend on language or human beings or anything else. This position can be seen reflected in language monist: we only need to find the one true language. However, insofar as we take language to latch on to reality, the availability of several languages seems to go counter this.

(Q3) Does language pluralism imply that metaphysical realism if false?

I want to argue that the correct answer to Q3 is 'no'. Rather, what this shows is that there is a gap between language and reality. Nevertheless, there seem to be epistemological consequences, viz., we need an account of how we get to know particular metaphysical truths if the underlying language is allowed to change. This leads to the following question:

(Q4) Can we understand metaphysics as modelling?

Science, when studying nature, proposes models of nature. These models are often local, i.e., not to be applied to domains other than their intended one. Can we have a similar picture of metaphysics? In particular, can we take the languages as providing us with the models? This also connects to a different topic:

(Q5) Can we spell out models as explications?

An explication considers particular concepts and proposes better ones. As such, explications are allowed to introduce dissimilarities to what is being explicated - a feature they share with models. I conjecture that the analogy is even more far reaching: we can understand models as explications.