scholarly journals Against the Russellian Open Future

Mind ◽  
2017 ◽  
Vol 126 (504) ◽  
pp. 1217-1237 ◽  
Author(s):  
Anders J Schoubye ◽  
Brian Rabern
Keyword(s):  
Classical Logic ◽  
Definite Descriptions ◽  
Future Contingents ◽  
Open Future ◽  
The Future ◽  
Law Of Excluded Middle ◽  
The Law ◽  
Excluded Middle

Abstract Todd (2016) proposes an analysis of future-directed sentences, in particular sentences of the form ‘will()’, that is based on the classic Russellian analysis of definite descriptions. Todd’s analysis is supposed to vindicate the claim that the future is metaphysically open while retaining a simple Ockhamist semantics of future contingents and the principles of classical logic, i.e. bivalence and the law of excluded middle. Consequently, an open futurist can straightforwardly retain classical logic without appeal to supervaluations, determinacy operators, or any further controversial semantical or metaphysical complication. In this paper, we will show that this quasi-Russellian analysis of ‘will’ both lacks linguistic motivation and faces a variety of significant problems. In particular, we show that the standard arguments for Russell's treatment of definite descriptions fail to apply to statements of the form ‘will()’.

The Open Future

2021 ◽  
Author(s):  
Patrick Todd
Keyword(s):  
Classical Logic ◽  
Philosophy Of Religion ◽  
Future Contingents ◽  
Open Future ◽  
Radical Interpretation ◽  
Norms Of Assertion ◽  
The Future ◽  
The Open Future ◽  
Patrick Todd

In The Open Future: Why Future Contingents are All False, Patrick Todd launches a sustained defense of a radical interpretation of the doctrine of the open future, one according to which all claims about undetermined aspects of the future are simply false. Todd argues that this theory is metaphysically more parsimonious than its rivals, and that objections to its logical and practical coherence are much overblown. Todd shows how proponents of this view can maintain classical logic, and argues that the view has substantial advantages over Ockhamist, supervaluationist, and relativist alternatives. Todd draws inspiration from theories of “neg-raising” in linguistics, from debates about omniscience within the philosophy of religion, and defends a crucial comparison between his account of future contingents and certain more familiar theories of counterfactuals. Further, Todd defends his theory of the open future from the charges that it cannot make sense of our practices of betting, makes our credences regarding future contingents unintelligible, and is at odds with proper norms of assertion. In the end, in Todd’s classical open future, we have a compelling new solution to the longstanding “problem of future contingents”.

Reconsidering Kant’s Rejection of Indirect Arguments in Transcendental Philosophy

2021 ◽  
pp. 1-19
Author(s):  
Marcel Buß
Keyword(s):  
Immanuel Kant ◽  
Explanatory Power ◽  
Transcendental Philosophy ◽  
Point Of View ◽  
Transcendental Arguments ◽  
Mathematical Proofs ◽  
Law Of Excluded Middle ◽  
The Law ◽  
Excluded Middle ◽  
Insight Into

Abstract Immanuel Kant states that indirect arguments are not suitable for the purposes of transcendental philosophy. If he is correct, this affects contemporary versions of transcendental arguments which are often used as an indirect refutation of scepticism. I discuss two reasons for Kant’s rejection of indirect arguments. Firstly, Kant argues that we are prone to misapply the law of excluded middle in philosophical contexts. Secondly, Kant points out that indirect arguments lack some explanatory power. They can show that something is true but they do not provide insight into why something is true. Using mathematical proofs as examples, I show that this is because indirect arguments are non-constructive. From a Kantian point of view, transcendental arguments need to be constructive in some way. In the last part of the paper, I briefly examine a comment made by P. F. Strawson. In my view, this comment also points toward a connection between transcendental and constructive reasoning.

7. Deducing

2020 ◽  
pp. 74-88
Author(s):  
Timothy Williamson
Keyword(s):  
Modal Logic ◽  
Classical Logic ◽  
Logical Inference ◽  
Disjunctive Syllogism ◽  
Philosophical Concept ◽  
The Law ◽  
The Difference ◽  
Excluded Middle

Detective work is an important tool in philosophy. ‘Deducing’ explains the difference between valid and sound arguments. An argument is valid if its premises are true but is only sound if the conclusion is true. The Greek philosophers identified disjunctive syllogism—the idea that if something is not one thing, it must be another. This relates to another philosophical concept, the ‘law of the excluded middle’. An abduction is a form of logical inference which attempts to find the most likely explanation. Modal logic, an extension of classical logic, is a popular branch of logic for philosophical arguments.

On Weakening the Law of Excluded Middle

Dialogue ◽  
1966 ◽  
Vol 5 (2) ◽  
pp. 232-236
Author(s):  
Douglas Odegard
Keyword(s):  
Law Of Excluded Middle ◽  
The Law ◽  
Excluded Middle

Let us use ‘false’ and ‘not true’ (and cognates) in such a way that the latter expression covers the broader territory of the two; in other words, a statement's falsity implies its non-truth but not vice versa. For example, ‘John is ill’ cannot be false without being nontrue; but it can be non-true without being false, since it may not be true when ‘John is not ill’ is also not true, a situation we could describe by saying ‘It is neither the case that John is ill nor the case that John is not ill.’

The Law of Excluded Middle

Mind ◽  
1978 ◽  
Vol LXXXVII (2) ◽  
pp. 161-180 ◽  
Author(s):  
NEIL COOPER
Keyword(s):  
Law Of Excluded Middle ◽  
The Law ◽  
Excluded Middle

Frege's theorem in a constructive setting

1999 ◽  
Vol 64 (2) ◽  
pp. 486-488 ◽  
Author(s):  
John L. Bell
Keyword(s):  
Set Theory ◽  
Natural Numbers ◽  
The Family ◽  
Power Set ◽  
Law Of Excluded Middle ◽  
The Law ◽  
Image Position ◽  
Excluded Middle ◽  
Intuitionistic Set Theory

By Frege's Theorem is meant the result, implicit in Frege's Grundlagen, that, for any set E, if there exists a map υ from the power set of E to E satisfying the conditionthen E has a subset which is the domain of a model of Peano's axioms for the natural numbers. (This result is proved explicitly, using classical reasoning, in Section 3 of [1].) My purpose in this note is to strengthen this result in two directions: first, the premise will be weakened so as to require only that the map υ be defined on the family of (Kuratowski) finite subsets of the set E, and secondly, the argument will be constructive, i.e., will involve no use of the law of excluded middle. To be precise, we will prove, in constructive (or intuitionistic) set theory, the followingTheorem. Let υ be a map with domain a family of subsets of a set E to E satisfying the following conditions:(i) ø ϵdom(υ)(ii)∀U ϵdom(υ)∀x ϵ E − UU ∪ x ϵdom(υ)(iii)∀UV ϵdom(5) υ(U) = υ(V) ⇔ U ≈ V.Then we can define a subset N of E which is the domain of a model of Peano's axioms.

scholarly journals Validating Brouwer's continuity principle for numbers using named exceptions

2017 ◽  
Vol 28 (6) ◽  
pp. 942-990 ◽  
Author(s):  
VINCENT RAHLI ◽  
MARK BICKFORD
Keyword(s):  
Equivalence Relation ◽  
Dependent Types ◽  
Proof Assistant ◽  
Continuity Theorem ◽  
Continuity Principle ◽  
Fan Theorem ◽  
Law Of Excluded Middle ◽  
The Law ◽  
Intuitionistic Mathematics ◽  
Excluded Middle

This paper extends the Nuprl proof assistant (a system representative of the class of extensional type theories with dependent types) withnamed exceptionsandhandlers, as well as a nominalfreshoperator. Using these new features, we prove a version of Brouwer's continuity principle for numbers. We also provide a simpler proof of a weaker version of this principle that only uses diverging terms. We prove these two principles in Nuprl's metatheory using our formalization of Nuprl in Coq and reflect these metatheoretical results in the Nuprl theory as derivation rules. We also show that these additions preserve Nuprl's key metatheoretical properties, in particular consistency and the congruence of Howe's computational equivalence relation. Using continuity and the fan theorem, we prove important results of Intuitionistic Mathematics: Brouwer's continuity theorem, bar induction on monotone bars and the negation of the law of excluded middle.

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