On the Role of Entanglement in Schroedinger's Cat Paradox

In this paper we re-investigate the core of Schroedinger's 'cat paradox'. We argue that one has to distinguish clearly between superpositions of macroscopic cat states and superpositions of entangled states which comprise both the state of the cat. It is shown, that in the first instance recurrence to decoherence or other mechanisms is not necessary in this special case in order to explain the absence of macroscopic superpositions. Additionally, we present modified versions of two quantum optical experiments as experimenta crucis. Applied rigorously, quantum mechanical formalism reduces the problem to a mere pseudo-paradox.Comment: 10 pages; LaTeX; contact information update

Direct reference and the Goldbach puzzle

. This is also known as the Neo-Russellian theory. Using truth ascriptions with names designating propositions, such as ‘Goldbach's conjecture’, in this paper, I will argue that, together with highly plausible principles regarding a priori knowledge, the Neo-Russellian theory leads to unacceptable consequences. I will call this ‘the Goldbach puzzle’. Since the solution to the Goldbach puzzle cannot be to reject the discussed principles regarding a priori knowledge, the puzzle will undermine the Neo-Russellian theory

The multiple relation theory and Schiffer’s puzzle

Following Russell, philosophers like Moltmann, Jubien, Boër, and Newman analyse ‘John believes that Mary is French’ as ‘R (John, the property of being French, Mary)’, instead of analysing it as ‘R (John, that Mary is French)’. Thus, for these philosophers, instead of relations holding between agents and truth-bearing entities (propositions), propositional attitude verbs, like ‘belief’, express relations holding between agents and the properties and objects our thoughts and speech acts are about. This is also known as the Multiple Relation Theory. In this paper, I will discuss the Multiple Relation Theory primarily in connection with a problem known as Schiffer’s puzzle. Schiffer first presented the puzzle to argue against the so called direct-reference theory of belief reports advocated, among others, by Salmon and Braun. I will argue that, unlike the direct-reference theory of belief reports, the Multiple Relation Theory does not provide a solution to Schiffer’s puzzle. In this connection, I will also discuss a slight modification of the Multiple Relation Theory according to which the ways the properties and objects our thoughts and speech acts are about are presented to us are part of the truth-conditions of sentences like ‘John believes that Mary is French’. We will see that prima facie such a contextualist version of the Multiple Relation Theory provides a solution to Schiffer’s puzzle. However, concluding, I will argue with new Schiffer cases that, ultimately, also a contextualist version of the Multiple Relation Theory cannot explain all instances of Schiffer’s puzzle. This will undermine the Multiple Relation Theory in general

Brains in Vats and Semantic Externalism: New Hope for the Skeptic

Different thought experiments have been offered to argue for the skeptical claim that sound empirical knowledge is impossible. One of these thought experiments assumes that we are eternal brains in a vat with systematically delusory experiences. In (Putnam 1981), Putnam responds to the skeptical challenge that contrary to our initial assumption we can know a priori, i.e. independent from experience, that we aren’t eternal brains in a vat. Putnam argues that the skeptical hypothesis that we are eternal brains in a vat is inconsistent with the received view regarding reference and truth, semantic externalism, which says that a referential expression e refers to an object o if and only if e is appropriately causally related to o. There are different versions of Putnam’s argument. In this paper, I will discuss the three main versions of the argument; i.e. a reconstruction of Putnam’s original argument in (Putnam 1981), Brueckner’s simple argument (Brueckner 2003; 2016, Section 3 and 4), and a reconstruction of Brueckner’s disjunctive argument (Brueckner 2016, Section 4). It is generally assumed that Putnam’s original argument does not show that the skeptical hypothesis that we are eternal brains in a vat is inconsistent with semantic externalism. In this paper, I will argue that the same is true of Brueckner’s simple argument and of Brueckner’s disjunctive argument. Although from this it won’t follow that semantic externalism is consistent with the skeptical hypothesis, it will show that it is also not yet decided that it is not

Brains in Vats and Semantic Externalism: New Hope for the Skeptic

Different thought experiments have been offered to argue for the skeptical claim that sound empirical knowledge is impossible. One of these thought experiments assumes that we are eternal brains in a vat with systematically delusory experiences. In (Putnam 1981), Putnam responds to the skeptical challenge that contrary to our initial assumption we can know a priori, i.e. independent from experience, that we aren’t eternal brains in a vat. Putnam argues that the skeptical hypothesis that we are eternal brains in a vat is inconsistent with the received view regarding reference and truth, semantic externalism, which says that a referential expression e refers to an object o if and only if e is appropriately causally related to o. There are different versions of Putnam’s argument. In this paper, I will discuss the three main versions of the argument; i.e. a reconstruction of Putnam’s original argument in (Putnam 1981), Brueckner’s simple argument (Brueckner 2003; 2016, Section 3 and 4), and a reconstruction of Brueckner’s disjunctive argument (Brueckner 2016, Section 4). It is generally assumed that Putnam’s original argument does not show that the skeptical hypothesis that we are eternal brains in a vat is inconsistent with semantic externalism. In this paper, I will argue that the same is true of Brueckner’s simple argument and of Brueckner’s disjunctive argument. Although from this it won’t follow that semantic externalism is consistent with the skeptical hypothesis, it will show that it is also not yet decided that it is not