{"id":5410,"date":"2017-06-20T12:50:16","date_gmt":"2017-06-20T12:50:16","guid":{"rendered":"https:\/\/maverickphilosopher.blog\/index.php\/2017\/06\/20\/a-pyrrhonian-puzzle\/"},"modified":"2017-06-20T12:50:16","modified_gmt":"2017-06-20T12:50:16","slug":"a-pyrrhonian-puzzle","status":"publish","type":"post","link":"https:\/\/maverickphilosopher.blog\/index.php\/2017\/06\/20\/a-pyrrhonian-puzzle\/","title":{"rendered":"A Quasi-Pyrrhonian Metaphilosophical Puzzle"},"content":{"rendered":"

Some of us are tempted by the metathesis (MT) that every substantive philosophical thesis is such that the arguments for it and the arguments against it are equally plausible and thus 'cancel out.' But the metathesis is itself a philosophical thesis. So if the metathesis is true, then every argument in support of it is cancelled out by an equally plausible argument against it.  But then (MT), if true, is such that we cannot have any good reason to accept it.<\/span><\/p>\n

Is there a genuine problem here for a latter-day quasi-Pyrrhonian who subscribes to the metathesis?<\/span><\/p>\n

Definitions<\/strong><\/span><\/p>\n

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D1. An argument A1 for a thesis T cancels out<\/em> an argument A2 for the negation of T just in case both arguments are equally plausible to the producers(s)\/consumers(s) of the arguments, assuming that these individuals are 'competent practitioners.'<\/span><\/p>\n<\/blockquote>\n

Plausibility is relative to an arguer and his audience, if any.  Thus plausibility is unlike soundness, which is absolute, like truth herself.  Note that there cannot be sound arguments both for a thesis and its negation. For if there is a sound argument for T, then T is true. And if there is a sound argument for ~T, then ~T is true. This is 'fallout' from the definition of 'sound,' see D2 below. But then (T & ~T) is true which violates the Law of Non-Contradiction.<\/span><\/p>\n

Canceling out<\/em> is symmetrical: If A1 cancels A2, then A2 cancels A1. It seems to follow that canceling out is also conditionally reflexive, which is to say that if A1 cancels A2, then A1 cancels itself. Right? <\/span><\/p>\n

A competent practitioner is not the same as an epistemic peer.  A number of individuals may be epistemic peers, but all incompetent. I won't try for a crisp definition of 'competent practitioner,' but if Tom is a competent practitioner in the philosophy of religion, say, then he is a a sincere truth seeker, not a quibbler or a sophist; he knows logic and the empirical disciplines that bear upon the arguments he is discussing; he is familiar with the relevant literature; and so on.<\/span><\/p>\n

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D2. An argument is sound just in case it is valid and all of its premises are true.<\/span><\/p>\n

D3. An argument for a thesis is unopposed just in case there is no argument for its negation plausible to all competent practitioners.<\/span><\/p>\n

D4. A proposition is rationally acceptable just in case it involves no logical contradiction, and coheres with the rest of what we know or justifiably believe.<\/span><\/p>\n<\/blockquote>\n

Rational acceptability, like plausibility, and unlike truth, is a relative property: That water is an element was rationally acceptable to the ancient Greeks, but not to us.<\/span><\/p>\n

The Puzzle as an Aporetic Tetrad<\/strong> <\/span><\/p>\n

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1) Every substantive philosophical thesis is such that the arguments pro et contra<\/em> cancel out. (MT)<\/span><\/p>\n

2) MT is a philosophical thesis.<\/span><\/p>\n

3) A philosophical thesis is rationally acceptable only if there is at least one good unopposed argument for it.<\/span><\/p>\n

4) MT is rationally acceptable.<\/span><\/p>\n<\/blockquote>\n

Solutions<\/span><\/strong><\/span><\/p>\n

The quartet of propositions is inconsistent. Any three limbs, taken in conjunction, entail the negation of the remaining one. Which should we reject? (2) is not plausibly rejectable: metaphilosophy is a branch of philosophy.<\/span><\/p>\n

One could hold that the first three propositions are true, but the fourth is false. This implies that a proposition could be true but not rationally acceptable.  But if MT is true but not rationally acceptable, what reason could we have for believing it?<\/span><\/p>\n

A better solution of the tetrad is by rejection of (1). This is the position of the optimist about philosophical knowledge. He holds that some theses are supported by unopposed arguments and that we know what these arguments are.<\/span><\/p>\n

I accept (1) on the basis of strong inductive evidence which renders it rationally acceptable. Accepting as I do (1), (2), and (4), I must reject (3).  Well, why not?<\/span><\/p>\n

Why can't I say the following? <\/span><\/p>\n

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3*) A philosophical thesis is rationally acceptable just in case there are some good arguments for it accepted by some competent practitioners.<\/span><\/span><\/p>\n<\/blockquote>\n

Why Accept the Metathesis?<\/strong><\/span><\/p>\n

MT expresses a very bold claim; I imagine most philosophers would just deny it. To deny it is to affirm that there is at least one philosophical thesis that can be conclusively demonstrated.  Can anyone give me an example? It has to be a substantive thesis, though, not, for example the thesis that it is contradictory to hold that it is absolutely true that all truths are relative.  Here are some examples of substantive philosophical theses:<\/span><\/span><\/p>\n