Re: William T. Parry gets rid of Disjunction introduction

On 02/07/2026 17:40, olcott wrote:
> On 7/2/2026 1:31 AM, Mikko wrote:
>> On 01/07/2026 18:25, olcott wrote:
>>> On 7/1/2026 2:32 AM, Mikko wrote:
>>>> On 30/06/2026 16:55, olcott wrote:
>>>>> On 6/30/2026 3:10 AM, Mikko wrote:
>>>>>> On 29/06/2026 16:55, olcott wrote:
>>>>>>> On 6/28/2026 4:32 AM, Mikko wrote:
>>>>>>>> On 27/06/2026 21:29, olcott wrote:
>>>>>>>>> On 6/27/2026 1:24 PM, dbush wrote:
>>>>>>>>>> On 6/27/2026 2:03 PM, olcott wrote:
>>>>>>>>>>> On 6/27/2026 12:54 PM, dbush wrote:
>>>>>>>>>>>> On 6/27/2026 11:11 AM, polcott wrote:
>>>>>>>>>>>>> On 6/27/2026 2:08 AM, Mikko wrote:
>>>>>>>>>>>>>> On 26/06/2026 15:49, olcott wrote:
>>>>>>>>>>>>>>> On 6/26/2026 1:49 AM, Mikko wrote:
>>>>>>>>>>>>>>>> On 26/06/2026 04:32, olcott wrote:
>>>>>>>>>>>>>>>>> William T. Parry, Entailment Logics
>>>>>>>>>>>>>>>>> gets rid of Disjunction introduction
>>>>>>>>>>>>>>>>> to prevent the principle of explosion
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> A simple logical matrix and sequent calculus for
>>>>>>>>>>>>>>>>> Parry’s logic of Analytic Implication
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> The main and distinctive feature of PAI (and of the many
>>>>>>>>>>>>>>>>> systems of analytic implication belonging to its ilk) is
>>>>>>>>>>>>>>>>> the rejection of the classically valid principle of 
>>>>>>>>>>>>>>>>> Addition,
>>>>>>>>>>>>>>>>> sometimes also referred to as Disjunction Introduction. In
>>>>>>>>>>>>>>>>> other words, the principle leading from a formula ϕ to a
>>>>>>>>>>>>>>>>> disjunction of the form ϕ ∨ ψ, where ψ is an arbitrary
>>>>>>>>>>>>>>>>> formula. Parry blamed on this principle the derivability
>>>>>>>>>>>>>>>>> of the paradoxes of strict implication—given that it is
>>>>>>>>>>>>>>>>> famously featured in Lewis’ derivation of an arbitrary
>>>>>>>>>>>>>>>>> formula ψ from a contradiction of the form ϕ ∧ ¬ϕ.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> https://philarchive.org/archive/SZMASL
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> He also gets rid of an efficient way to convince people 
>>>>>>>>>>>>>>>> who don't
>>>>>>>>>>>>>>>> understand much of logic.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> As I recently showed in another post. I figured
>>>>>>>>>>>>>>> all this out on my own. I didn't even know that
>>>>>>>>>>>>>>> anyone else ever did this. I just knew that when
>>>>>>>>>>>>>>> trying to find out what is deduced from a set of
>>>>>>>>>>>>>>> premises that you cannot pop in another sentence
>>>>>>>>>>>>>>> from out of nowhere and get a correct conclusion.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> By popping in another sentence from out of nowhere
>>>>>>>>>>>>>>> (as it shows above) the principle of explosion is
>>>>>>>>>>>>>>> derived.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> The usual meaning of proof is a sequence of statement 
>>>>>>>>>>>>>> where eachstatement either is a premis or follows from one 
>>>>>>>>>>>>>> or more earlier
>>>>>>>>>>>>>> statements 
>>>>>>>>>>>>>
>>>>>>>>>>>>> Except with Disjunction introduction, that is its problem.
>>>>>>>>>>>>
>>>>>>>>>>>> So you're saying that in the following natural language 
>>>>>>>>>>>> statement:
>>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> It is a key issue in that it creates the
>>>>>>>>>>> psychotic break from reality known as the
>>>>>>>>>>> Principle of Explosion, otherwise it may
>>>>>>>>>>> make no difference at all.
>>>>>>>>>>>
>>>>>>>>>>> Stay on topic or I will block you.
>>>>>>>>>>
>>>>>>>>>> Explain in detail how the below which you dishonestly trimmed 
>>>>>>>>>> is off- topic.
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>> The topic is how Disjunction introduction enables the
>>>>>>>>> Principle of Explosion.
>>>>>>>>
>>>>>>>> It does not. In any sensible logic every tautology is provable.
>>>>>>>> Then the principle of explosion follows.
>>>>>>>
>>>>>>> POE is unprovable in both of these more sensible systems
>>>>>>> of logic.
>>>>>>
>>>>>> THe expression "these system" above does not denote.
>>>>>
>>>>> Parry’s logic of Analytic Implication
>>>>
>>>> If the intent was to include that in the denotation you failed
>>>> to say something important.
>>
>>> Parry’s logic of Analytic Implication
>>> and Relevance logic are two sensible systems
>>> that get rid of the Principle of Explosion.
>>
>> Getting rid of the principle of explosion makes as much sense as
>> getting rid of fire alarms. It makes much more sense to get rid
>> of fires and false premises.
> 
> Then you are irrational

Matter of opinion, but I think that most of people would consder
getting rid of fires is more rational that getting rid of fire
alarms.

-- 
Mikko