24 What is modal logic for? 2013-01-31T18:49:04.213

15 What are the practical applications of modal logic? 2015-05-17T22:45:05.490

14 How do I go from ◊∃x□[∃y(y=x) ∧ Mx] to ∃x□[∃y(y=x) ∧ Mx]? 2013-07-12T01:26:08.423

13 In modal logic, why not 'possibly p' → 'not necessarily p'? 2014-03-27T20:14:20.350

10 How is Kripke-style modal logic distinct from classical propositional logic with additional axioms? 2013-11-02T23:32:57.427

8 Modal Logic: a question concerning accessibility 2013-03-13T07:24:36.340

8 Are there mathematical properties a mathematical object might have only contingently? 2013-03-21T19:01:41.090

8 Is there a name for each individual's perceived sphere of reality? 2013-09-01T07:51:11.633

8 How to Prove "Possibly P if Necessarily P" in Kripke Modal Logic? 2014-03-30T19:46:47.823

8 Is there any relation beetwen justification logic and type theory? 2014-09-01T13:27:02.903

8 What's a good source for refreshing my formal logic skills prior to graduate school? 2015-05-22T18:41:07.293

8 Is it possible to not know that one knows p? 2016-11-27T04:20:34.320

8 Should truth entail possible truth? 2019-04-12T19:35:22.450

7 Nonexistence and invalid formulas in modal logic 2013-06-27T07:02:26.500

7 Is there modal logic without possible worlds? 2016-02-29T22:09:07.147

7 What is the explanation for inferring existence in every possible world from existence in some in Plantinga's Ontological Argument? 2017-05-04T15:56:34.193

6 What determines accessibility of possible worlds? 2013-05-23T09:55:36.247

6 Can logic be significantly geometrised? 2013-09-21T19:30:04.423

6 How does Plantinga's free will defense of God's benevolence work? 2014-10-02T00:10:50.147

6 Assuming P means the same as Q and Bob believes P and is aware that P means the same as Q, can we conclude he believes Q? 2014-12-23T04:08:01.470

6 Indiscernibility of possible worlds 2015-07-01T21:18:10.807

6 Why is Hesperus necessarily Phosphorus? 2015-08-20T21:31:32.747

6 What is the difference between a probability and a possibility? 2015-09-30T14:45:51.620

6 Has any philosopher ever claimed that possibility can't really be tensed? 2017-09-17T09:35:53.127

6 Why substitutivity doesn't work in an intensional context? 2017-10-03T11:22:56.677

6 What does □□p mean? 2020-03-11T16:44:08.347

5 Establishing Incompletenes of Modal LPC 2013-01-09T23:04:32.070

5 Does modal realism dispense with Occams razor or embodies it? 2013-02-12T22:40:44.897

5 Rigid designators, equality and functions in many-valued logic and (simple) quantified modal logic 2013-08-22T00:35:22.870

5 Is there such a thing as provability of provability? 2013-11-17T12:42:40.473

5 What's the difference between being spatiotemporally isolated and causally isolated? 2014-03-09T15:22:23.473

5 What are the prerequisites for studying modal logic? 2014-05-08T02:54:55.790

5 Classical possible worlds semantics 2014-05-20T20:01:50.100

5 Is knowledge really related to propositional modal logic? 2014-05-29T17:34:58.563

5 Why is it wrong to deduce determinism from a logical law? 2014-12-16T05:32:57.020

5 What do necessity and possibility mean in Aquinas' Third Way argument for the existence of God? 2015-01-12T06:34:02.387

5 Need Help Fully Understanding the Claim: Every normal modal logic, L, is an extension of K 2015-04-22T18:37:24.847

5 What are the objections to the axioms of modal logic? 2015-08-13T16:35:15.873

5 Conditional logic - how to apply a conditional with complex antecedent in tableaux? 2015-10-02T13:11:10.197

5 Is Modal Logic Logic? 2016-10-24T10:02:21.433

5 Does semantic externalism imply modal realism? 2017-01-30T19:34:14.217

5 What is Quine's perspective on probability? 2018-09-23T15:01:07.750

5 Does anyone have a proof checker they prefer using for modal logic? 2018-10-01T18:08:08.867

5 Can possible-but-non-actual objects have accidental properties? 2018-10-22T16:51:18.030

5 Where is the fallacy in Seth Yalcin's counterexample to the modus tollens? 2020-02-17T12:54:21.040

5 Is it consistent to say "X is possible but false"? 2021-01-05T03:18:52.603

4 For the modal realist, do possible individuals (and worlds) exist necessarily? 2013-03-24T00:31:17.177

4 Reasoning in S5 2013-05-19T09:34:48.647

4 Logic Notation Question: [[A]] vs. ⌈A⌉ 2013-08-17T22:08:27.783

4 I don't understand why Kant's definition of an analytic concept can't be expressed in terms of intensional logic 2013-08-18T23:41:32.157

4 Is this a reasonable weak classical Deontic Logic? 2013-08-21T15:30:38.387

4 Does the finitary proof of the consistency of relevant PA shows that first order PA is irrelevant? 2013-09-20T09:37:51.873

4 What is Ackermanns 'admissibility of gamma' in relevance logic? 2013-09-20T16:48:12.730

4 Appropriate formulation of the necessitation rule from modal logic 2013-11-11T23:58:17.840

4 What is the difference between 'instantiate' and 'exemplify', if any? 2013-12-10T19:05:12.173

4 Can three valued logic serve as an adequate basis for a (nontraditional) modal logic? 2014-03-04T08:53:25.350

4 What exactly is metaphysical possibility? 2014-05-17T10:15:42.430

4 Classical and Medieval Scholars on Modal Logic 2014-06-20T07:21:26.543

4 Who Invented the Modal Fallacy? 2014-06-21T05:17:14.923

4 Formal Modal Logic and Metaphysics 2015-03-14T23:48:21.007

4 Please explain this paragraph of van Inwagen (First Argument for Incompatibilism) 2015-04-29T12:44:16.260

4 What is the connection between temporal and epistemic knowledge? 2015-06-21T00:14:45.950

4 Many-worlds interpretation of QM and modal realism 2015-07-10T20:22:25.157

4 Why did many valued logic fail in describing modal logic? 2016-01-25T17:25:03.260

4 According to modal realism, how many possible worlds are there? 2016-04-20T09:39:49.883

4 Is there anyone who believes that all modal statements are meaningless or trivial? 2016-11-15T04:24:56.217

4 Is it provable that epistemically possible (possible for all I know) does not imply possible? 2017-03-24T20:39:14.160

4 How many equivalence classes does the accessiblity relation have in S5? 2018-01-03T20:22:43.410

4 How to construct a counter-model of □P --> □◊P in T and K? 2018-04-05T00:16:42.167

4 How does the concept of the 'virtual' (Deleuze) relate to 'counterfactuals' (Lewis)? 2018-05-07T10:23:06.997

4 Does S4 (and B) hold for the strongest interpretations of ♢ and □? 2019-02-12T09:23:11.817

4 What are good sources on vivid designators? 2019-06-12T21:46:32.750

4 Are there famous unsolved problems in logic akin to the Millenium Prize problems? 2020-07-08T07:23:14.063

4 A possible formal failure made by Kripke? 2020-07-28T04:10:38.833

4 Is every world accessible to itself? 2020-09-20T10:22:00.120

3 One-placed intersection operator 2013-04-26T02:54:44.253

3 "It is epistemically necessary that P" versus "It is known that P" 2013-08-15T20:01:33.093

3 What is the connection between provability logic & Gödel's first incompleteness theorem? 2013-08-18T07:36:47.500

3 Which of the following sentential operators are truth functional ? Why? 2014-04-10T21:23:42.603

3 What is the Difference between Vagueness and Indeterminacy? 2014-06-20T15:29:15.880

3 Are the truths of euclidean plane geometry contingent truths? 2014-06-28T17:21:26.977

3 What does w ∈ V(p) mean? 2014-08-05T21:05:59.563

3 What kind of conditional does Nozick use in his theory of knowledge? 2014-11-02T03:19:52.670

3 Questions from a new introduction to modal logic by Hughes and Cresswell 2015-05-20T06:40:30.657

3 Introduction Modal Logic with emphasis on metaphysics - free will particularly - and also mathematical logic 2015-06-03T19:06:54.767

3 Interpretation of implication symbol in modal logic 2015-06-13T14:03:46.680

3 Does Aristotle recognize the Modal scope fallacy in his rejection of the sea battle argument? 2015-08-16T00:39:31.797

3 Intrinsically versus necessarily 2015-09-01T16:17:03.800

3 How can a tautology not be necessarily true? 2015-10-31T03:28:52.257

3 What is the name of the position which claims that "everything that is possible, exists"? 2015-11-19T00:58:03.000

3 Does modal logic have truth tables? 2015-11-25T17:15:15.640

3 What is the difference between ∃ (existence) and A (actuality)? 2016-04-16T19:57:03.043

3 Can one be a Modal Realist without also having to incorporate the existence of impossible worlds? 2016-05-23T14:59:01.347

3 Defining logical possibility without circularity 2016-08-16T23:49:37.183

3 If everything is possible, is it possible for something to be impossible? 2016-09-01T20:55:00.603

3 Classes of frames in Modal logic 2016-09-20T16:44:02.540

3 Does this modal ontological argument prove the existence of God? 2017-03-25T10:01:03.627

3 A problem with Modal Logic (necessary truths) 2017-05-03T17:47:32.273

3 Getting started with reading papers in (philosophical) logic 2017-09-10T10:26:27.140