Announcement

Collapse

Philosophy 201 Guidelines

Cogito ergo sum

Here in the Philosophy forum we will talk about all the "why" questions. We'll have conversations about the way in which philosophy and theology and religion interact with each other. Metaphysics, ontology, origins, truth? They're all fair game so jump right in and have some fun! But remember...play nice!

Forum Rules: Here
See more
See less

When does proving one's truth claims come to an end?

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • If all you've ever observed are white swans, then a black swan is impossible. Until you see one.
    Strangest usage of impossible I've ever read.
    Many and painful are the researches sometimes necessary to be made, for settling points of [this] kind. Pertness and ignorance may ask a question in three lines, which it will cost learning and ingenuity thirty pages to answer. When this is done, the same question shall be triumphantly asked again the next year, as if nothing had ever been written upon the subject.
    George Horne

    Comment


    • Originally posted by mattbballman31 View Post
      Strangest usage of impossible I've ever read.
      It's been a strange conversation.

      Comment


      • I still don't see how that usage would ever be apprioriate.
        Many and painful are the researches sometimes necessary to be made, for settling points of [this] kind. Pertness and ignorance may ask a question in three lines, which it will cost learning and ingenuity thirty pages to answer. When this is done, the same question shall be triumphantly asked again the next year, as if nothing had ever been written upon the subject.
        George Horne

        Comment


        • Originally posted by mattbballman31 View Post
          Strangest usage of impossible I've ever read.
          So Matt, what do you think of paralogic? I can't figure out their point - that true contradictions are possible?
          Atheism is the cult of death, the death of hope. The universe is doomed, you are doomed, the only thing that remains is to await your execution...

          https://www.youtube.com/watch?v=Jbnueb2OI4o&t=3s

          Comment


          • Originally posted by seer View Post
            Is your statement both true and not true? How could we know?
            Try breaking it up into two separate questions.

            Comment


            • Originally posted by seer View Post
              So Matt, what do you think of paralogic? I can't figure out their point - that true contradictions are possible?
              Paraconsistent logic denies the universal applicability of the law of excluded middle. Graham Priest is their go-to guy. I'm not convinced by it at all. It's typically 'proven' using propositions with vague predicates that no Aristotelian would ever dispute. Propositions with vague predicates (e.g. bald) have a third value (not true or false, but neither true nor false) to account for the vagueness. I believe there were other examples, but I can't remember off the top of my head. To say the least, the majority of logicians disagree with Priest.
              Many and painful are the researches sometimes necessary to be made, for settling points of [this] kind. Pertness and ignorance may ask a question in three lines, which it will cost learning and ingenuity thirty pages to answer. When this is done, the same question shall be triumphantly asked again the next year, as if nothing had ever been written upon the subject.
              George Horne

              Comment


              • Originally posted by Stoic View Post
                Try breaking it up into two separate questions.

                1.Is your statement both true and not true?

                2.How could we know?
                Atheism is the cult of death, the death of hope. The universe is doomed, you are doomed, the only thing that remains is to await your execution...

                https://www.youtube.com/watch?v=Jbnueb2OI4o&t=3s

                Comment


                • Originally posted by mattbballman31 View Post
                  Paraconsistent logic denies the universal applicability of the law of excluded middle. Graham Priest is their go-to guy. I'm not convinced by it at all. It's typically 'proven' using propositions with vague predicates that no Aristotelian would ever dispute. Propositions with vague predicates (e.g. bald) have a third value (not true or false, but neither true nor false) to account for the vagueness. I believe there were other examples, but I can't remember off the top of my head. To say the least, the majority of logicians disagree with Priest.
                  Thanks, I find it rather confusing.
                  Atheism is the cult of death, the death of hope. The universe is doomed, you are doomed, the only thing that remains is to await your execution...

                  https://www.youtube.com/watch?v=Jbnueb2OI4o&t=3s

                  Comment


                  • They're just being provocative to secure tenure,
                    Many and painful are the researches sometimes necessary to be made, for settling points of [this] kind. Pertness and ignorance may ask a question in three lines, which it will cost learning and ingenuity thirty pages to answer. When this is done, the same question shall be triumphantly asked again the next year, as if nothing had ever been written upon the subject.
                    George Horne

                    Comment


                    • Originally posted by mattbballman31 View Post
                      They're just being provocative to secure tenure,
                      Here's an interesting source.

                      https://legacy.earlham.edu/~peters/c...ne%20is%20true.

                      Comment


                      • Originally posted by Stoic View Post
                        How about you explain this with an example? That would be nice.
                        Atheism is the cult of death, the death of hope. The universe is doomed, you are doomed, the only thing that remains is to await your execution...

                        https://www.youtube.com/watch?v=Jbnueb2OI4o&t=3s

                        Comment


                        • Originally posted by seer View Post
                          How about you explain this with an example? That would be nice.
                          I'm sure it would, but I'm no expert, nor do I claim to be one. Looking over Peter Suber's handout again, I can see that I've already made a number of errors in this thread.

                          I would point out that Peter Suber appears to be referenced pretty frequently, so it seems he knows what he's talking about.

                          Comment


                          • Originally posted by Stoic View Post
                            I'm sure it would, but I'm no expert, nor do I claim to be one. Looking over Peter Suber's handout again, I can see that I've already made a number of errors in this thread.
                            Oh good, it's not just me!
                            Atheism is the cult of death, the death of hope. The universe is doomed, you are doomed, the only thing that remains is to await your execution...

                            https://www.youtube.com/watch?v=Jbnueb2OI4o&t=3s

                            Comment


                            • Given a statement and its negation, p and ~p, the PNC asserts that at most one is true.
                              Not quite. Only one can be true, but it's also the case that they both can't be false, if the options are an exclusive disjunction. PEDC is just semantically redundant. PNC has nothing to do with inclusive disjunctions. These are called contraries, not contradictories. So, regarding PNC, contraries don't come into the picture. P or ~P wouldnt' be inclusive; P or Q might be.

                              The three principles can be proved in such a logic, but any such proof would be viciously circular.
                              This doesn't bother those who make a distinction between premise and rule circularity, the latter of which isn't vicious.

                              Case 1. If the PNC were true of the world, and the PEM false, then there would be some pairs of contradictories for which neither member was true. The world would be underdetermined. The world would be thinner and more abstract than the PEDC would have it.
                              This makes no sense. If PNC is true, PEM follows, because of the nature of an exclusive disjunction. I don't care about inclusive disjunctions or contraries. And I wouldn't be talking about 'the world'; I'm talking about truth-theoretic propositions about states of affairs in or about that world.

                              Case 2. If the PEM were true of the world and the PNC false, then there would be some pairs of contradictories for which both members were true. The world would be overdetermined; it would be richer and more concrete (in Hegel's sense, more articulated or differentiated and more dense and continuous) than the PEDC would allow.
                              This also makes no sense, since if PEM is true, then given a pair of contradictories, they can't both be true. Hegel's dialectic muddies the waters and equivocates on 'truth'; Hegel doesn't talk about truth in terms of propositions, things are inimical within the wider context of his absolute idealism.

                              Consistent logics can be developed that enable us to describe these inconsistent states of affairs; see e.g. Rescher and Brandom, Logic of Inconsistency, Rowman and Littlefield, 1979.
                              The metalanguage of those consistent logics would all be using PEM and PNC.

                              Standard logic gets nowhere against dialetheism by insisting that contradictions are always false, for dialetheism admits this but adds that they are true too. If standard logic insists that contradictions are nothing but false, then it must justify this or else beg the question against dialetheism; but as we have seen, it is difficult to produce such a justification that is not viciously circular by presupposing the standard PEDC and hence the PNC that dialetheism has rejected.
                              Nope. Dialetheism has never had a good objection to the distinction between rule and premise circularity, the former of which isn't vicious.

                              Reversing dialetheism by denying the PEM but affirming the PNC is the intuitionistic school of mathematics, inspired by the work of L.E.J. Brouwer (1881-1967).
                              I reject intuitionism.

                              Aristotle's indirect proof of the PNC does not refute the PD. Aristotle argues that any denial of the PNC presupposes the PNC, for it wishes to be the denial and not also the affirmation of the PNC. A naive denial of the PNC that did not also affirm the PNC would be vulnerable to Aristotle's argument. But the PD understands that the falsehood of the PEDC is consistent (in the PD's own sense of consistency) with the truth of the PEDC; only the PEDC itself would forbid this. PD, then, both affirms and denies the PNC and thereby avoids Aristotle's argument.
                              PD is false.
                              Many and painful are the researches sometimes necessary to be made, for settling points of [this] kind. Pertness and ignorance may ask a question in three lines, which it will cost learning and ingenuity thirty pages to answer. When this is done, the same question shall be triumphantly asked again the next year, as if nothing had ever been written upon the subject.
                              George Horne

                              Comment


                              • Originally posted by mattbballman31 View Post
                                Not quite. Only one can be true, but it's also the case that they both can't be false, if the options are an exclusive disjunction. PEDC is just semantically redundant. PNC has nothing to do with inclusive disjunctions. These are called contraries, not contradictories. So, regarding PNC, contraries don't come into the picture. P or ~P wouldnt' be inclusive; P or Q might be.



                                This doesn't bother those who make a distinction between premise and rule circularity, the latter of which isn't vicious.



                                This makes no sense. If PNC is true, PEM follows, because of the nature of an exclusive disjunction. I don't care about inclusive disjunctions or contraries. And I wouldn't be talking about 'the world'; I'm talking about truth-theoretic propositions about states of affairs in or about that world.



                                This also makes no sense, since if PEM is true, then given a pair of contradictories, they can't both be true. Hegel's dialectic muddies the waters and equivocates on 'truth'; Hegel doesn't talk about truth in terms of propositions, things are inimical within the wider context of his absolute idealism.



                                The metalanguage of those consistent logics would all be using PEM and PNC.



                                Nope. Dialetheism has never had a good objection to the distinction between rule and premise circularity, the former of which isn't vicious.



                                I reject intuitionism.



                                PD is false.
                                It really appears that you have justified Suber's first sentence: "The Principle of Non-Contradiction (PNC) and Principle of Excluded Middle (PEM) are frequently mistaken for one another and for a third principle which asserts their conjunction."

                                His description of the PNC and PEM matches what I find elsewhere. Your claim that they are the same thing does not.

                                I would be more likely to take your claims seriously if you provided some links that back you up.

                                Comment

                                Related Threads

                                Collapse

                                Topics Statistics Last Post
                                Started by shunyadragon, 03-01-2024, 09:40 AM
                                160 responses
                                505 views
                                0 likes
                                Last Post JimL
                                by JimL
                                 
                                Started by seer, 02-15-2024, 11:24 AM
                                88 responses
                                354 views
                                0 likes
                                Last Post shunyadragon  
                                Started by Diogenes, 01-22-2024, 07:37 PM
                                21 responses
                                133 views
                                0 likes
                                Last Post shunyadragon  
                                Working...
                                X