Thursday, April 10, 2014

520: Arabic philosophy and Logic

At a given moment in history, when a society is not primarily occupied with hunting, gathering and farming to survive, it gets time to think beyond that.

We have seen it in Chinese culture, Indian culture and in Greece. And eventually we see it happen in Arabic culture too a 1000 years later than in Greece.

It was the advent of the Abbasid Caliphate (750–1258) that signaled the beginnings of an interest in philosophy on the part of the ruling elite. 

This was manifested itself in a translation movement which in the first place translated Syriac texts of philosophy into Arabic, but which later turned to the Aristotelian texts themselves and the commentaries written on them in late antiquity.

Syriac is a dialect of Middle Aramaic that was once spoken across much of the Fertile Crescent and Eastern Arabia. I already mentioned it in the previous lecture in relation to the origins of the Quran.

Having first appeared as a script in the 1st century AD after being spoken as an unwritten language for five centuries, Classical Syriac became a major literary language throughout the Middle East from the 4th to the 8th centuries.

The situation is thus: The function of the Prophet is to reveal the religious law (shari‘a) while the Imam unveils gradually to his disciples the inner meaning of the revelation through the ta’wil, which is going back to the original meaning of the Quran.

But there is more than just the explanation of meaning of words and statements. Man can’t be stopped to think past beliefs, question beliefs.

And this confronts us with the more fundamental questions like: Is this statement true? And if true, is it necessarily true or just accidentally? How do you validate the truth of a statement?

In fact, such questions belong to the greatest discoveries of our mind, because they ask for the way the mind operates in understanding life, the world.

You could say that after the standard religious answer in the form of a theological text, in this case the Quran, philosophers take the questioning one step further. They begin to reason.

We all reason. We try to figure out what is so, reasoning on the basis of what we already know. We try to persuade others that something is so by giving them reasons. 

Keep in mind that this is common practice for us today, but 790 CE this was innovative knowledge, new ways of looking at things, a formalized way of reasoning: logic.

Logic is the study of what counts as a good reason for what. and why. You have to understand this claim in a certain way, though. 'Here are two bits of reasoning - logicians call them inferences:

1. Rome is the capital of Italy, and this plane lands in Rome; so the plane lands in Italy.
2. Moscow is the capital of the USA; so you can't go to Moscow without going to the USA.

In each case, the claims before the 'so' - logicians call them premisses - are giving reasons; the claims after the ·so' - logicians call them conclusions- are what the reasons are supposed to be reasons for. 

The first piece of reasoning is fine; but the second is pretty hopeless, and wouldn't persuade anyone with an elementary knowledge of geography: the premiss, that Moscow is the capital of the USA, is simply false. 

Notice, though, that if the premiss had been true- if, say, the USA had bought the whole of Russia (not just Alaska) and had moved the White House to Moscow to be nearer the centres of power in Europe - the conclusion would indeed have been true. 

It would have followed from the premisses; and that is what logic is concerned with. It is not concerned with whether the premisses of an inference are true or false.

What philosophers became aware of was the fact, that there is a proposition which is in a way prior to every other truth: it is prior because it is a proposition which anyone who knows anything must accept and because it is impossible actually to disbelieve it. 

Which proposition that is and which the Arab philosophers learnt from Aristotle, I’ll reveal in the next lecture unless of course you already know or can guess…^_^

The Discussion

[13:31] herman Bergson: Thank you ^_^
[13:31] herman Bergson: Feel free to ask your questions or make your remarks :-)
[13:32] herman Bergson: Floor is yours...
[13:32] Debbie dB: Oh. - rereads last section...
[13:32] herman Bergson: an A if you have the answer Debbie ^_^
[13:32] Debbie dB: interesting lecture - thanks Herman. And hi friends ;)
[13:33] Bejiita Imako: hmm interesting, what proposition can that be really?
[13:34] herman Bergson: Well Bejiita is such common knowledge to us now......
[13:34] Bejiita Imako: i guess i ll get an "of course" moment when i find out
[13:34] Bejiita Imako:
[13:34] herman Bergson: Just imagine that in those days it was really a new insight
[13:35] herman Bergson: well maybe not  really a new insight...but finally stated in a formal way....
[13:35] bergfrau Apfelbaum: ty herman! ... interesting! and hi to Debbie:-)
[13:35] Bejiita Imako: its something totally logical for sure i bet
[13:35] Debbie dB: hmm... thinks that the proposition has to do with the need or ability ion?
[13:35] herman Bergson: Just a hint....we are talking about the discovery of LOGIC  here
[13:35] Lizzy Pleides: Did I understand right that the greek Philosophers have been translated first to Armaic and later to Syriac language?
[13:35] .: Beertje :.: this must lead us to a 'aha' moment...
[13:36] Debbie dB: If we ask a question, then there can be a proposition, and a reason.
[13:36] herman Bergson: The greek philosophers were in the beginning translated from Syriac which is a dialect of Middle Aramaic, Lizzy....
[13:37] herman Bergson: Later the Arabs began translating the original Greek texts...
[13:37] herman Bergson: Especially the works of Aristotle
[13:37] .: Beertje :.: and they made mistakes?
[13:38] herman Bergson: why that Beertje?
[13:38] .: Beertje :.: because of so many translations..mistakes are easy made
[13:38] herman Bergson: Lots of translators make mistakes ..yes....
[13:39] Lizzy Pleides: and we got the greek philosophy back when the arabs conquered europe
[13:39] herman Bergson: oh...for that you have endless  debates on how to translate some words....
[13:39] .: Beertje :.: f.i..the virgins seem to be grapes...
[13:39] herman Bergson: yes Lizzy...Aristotle came through Spain back into European philosophy
[13:40] herman Bergson: ahhh the 72 grapes :-)....the documentary I mentioned last time....yes fascinating...and disappointing for the martyres
[13:41] herman Bergson: ok...just to help you...
[13:41] herman Bergson: let me reveal the answer about that proposition :-)
[13:41] herman Bergson: .
[13:41] Debbie dB: Mind creaks with disuse...
[13:42] herman Bergson: The proposition in question is what we usually call the principle of non-contradiction: "it is impossible for the same thing to be both affirmed and denied of the same thing at the same time and in the same way''.
[13:42] herman Bergson: A is not not-A
[13:42] Debbie dB: ok. eureka.
[13:42] Debbie dB:  ✧✩**✩✧ G I G G L E S ✧✩**
[13:43] Bejiita Imako: a thing cant be both true and false at same time i guss
[13:43] Debbie dB: what about the need to ask the question, and then using A=A
[13:43] herman Bergson: seems so simple......
[13:43] Bejiita Imako: or something like that
[13:43] herman Bergson: yes use this idea every day.....
[13:43] Bejiita Imako: indeed
[13:43] herman Bergson: yet there is no way to proof it
[13:44] Debbie dB: If you dont ask what is A, if A doesnt exist, then A not equal A
[13:44] herman Bergson: neither to deny it because then you assume the same principle a priori :-)
[13:45] herman Bergson: no Debbie.....
[13:45] herman Bergson: then the proposition is A exists....or it is : A does not exist...
[13:45] herman Bergson: you have to ask one of the questions :-)
[13:46] Bejiita Imako: true false, there, not there , 1 0
[13:46] Debbie dB: Ok fair enough. but the theoretical answers only come when the question is asked.
[13:46] Bejiita Imako: sort of like that
[13:46] Bejiita Imako: one of them it must be
[13:47] Debbie dB: there are many answers that have no questions yet ;)
[13:47] herman Bergson: the core of the matter is that the content fo "A" is irrelevant.....
[13:47] Debbie dB: agreed.
[13:47] herman Bergson: whatever it is...the rule applies
[13:47] Debbie dB: and if it is irrelevant, then a may not = A
[13:48] Debbie dB: in logis its a X - or "dont care" condition
[13:48] herman Bergson: you only can claim that when you assume that A = A :-)
[13:48] herman Bergson: three values logic?
[13:49] Debbie dB: all logic uses yes, no, indeterminate, and dont care. see Karnaugh maps ;)
[13:49] herman Bergson: 0, 1, undecided?
[13:49] Debbie dB: nope - 0.1 dont care
[13:49] Debbie dB: as in not implicated in the answer.
[13:50] herman Bergson: Aristotle would have difficulty with that Debbie ^_^
[13:50] Debbie dB: I design logic circuits. standard boolean logic includes the states - and X
[13:50] herman Bergson: I'll check out Karnaugh :-)
[13:51] Debbie dB: dont know, and dont care
[13:51] Bejiita Imako: aaa you make things like cpus and similar?
[13:51] Debbie dB: yep
[13:51] Bejiita Imako: microchips
[13:51] Bejiita Imako: ok
[13:51] Bejiita Imako: that’s highly logical things indeed
[13:51] Bejiita Imako: and i like to program them
[13:51] Bejiita Imako:
[13:51] herman Bergson: You mean your designs are not binary Debbie?
[13:51] Debbie dB: and they work and can show A=A ;)
[13:52] Debbie dB: they are binary herman. the x and - are used to manipulate equations to remove redundancy.
[13:53] Debbie dB: The dash means - this input makes no difference
[13:53] herman Bergson: but this is not about truth is about do this ..or do't do this....or do nothing????
[13:53] Debbie dB: the x means - the output state doesn’t matter here.
[13:53] Debbie dB: you said it was logic, sir ;)
[13:54] Debbie dB: logic
[13:54] Bejiita Imako: well same analogy i guess
[13:54] Bejiita Imako: either you do = 1 = true or you dont = 0 = false
[13:54] herman Bergson: yes.....
[13:54] Debbie dB: or you think it matters, but it doesn’t.
[13:54] herman Bergson: or you ignore the output, which is either a 1 or 0 response too, I would say
[13:55] Debbie dB: yes.
[13:55] Bejiita Imako: yes
[13:55] herman Bergson: you just ignore the response...
[13:55] Bejiita Imako: 0 id say
[13:55] Debbie dB: it gets more complex with fuzzy logic - or multi level logic.
[13:55] herman Bergson: Ahh yes ....
[13:56] Bejiita Imako: however in some circuits things are off when "pulled high" = 1, the oposite of what would normally be
[13:56] herman Bergson: But in his Introduction to the Kritik der reiner Vernuft Kant said that since Aristotle logic hadn’t changed a bit ^_^
[13:56] Bejiita Imako: many flash memory input pins for ex uses this approach
[13:56] Bejiita Imako: 1 = off and 0 = true
[13:56] herman Bergson: and he was right in 1793 :-)
[13:56] Debbie dB: an inverter bejita - and all inverters represent upside- down question errrors ;)))
[13:56] Bejiita Imako: yes
[13:56] Bejiita Imako: true
[13:57] Bejiita Imako: or not gate
[13:57] herman Bergson: You are talking of non Aristotelian logic which was far beyond Arabic thinking in those days and would be for centuries :-))
[13:57] Debbie dB: The nice thing about humans is we add intuition to logic.
[13:58] Bejiita Imako: yes
[13:58] Debbie dB: lots of our daily reasoning is fuzzy.
[13:58] Bejiita Imako: hehe indeed
[13:58] herman Bergson: Just keep in mind that the A = A  "discovery" was really something in those days.....
[13:58] Debbie dB: I accept that herman.
[13:58] Lizzy Pleides: most decisions we make intuitive
[13:58] Bejiita Imako: ah
[13:59] herman Bergson: and it was closely related to epistemological and metaphysical thoughts
[14:00] herman Bergson: Well this was pretty techincal :-)
[14:00] Debbie dB: fair enough. removing the fuzz helps us to understand concepts better.
[14:00] Bejiita Imako:
[14:00] herman Bergson: But totally unknown to Aristotle , or the Arab philosophers
[14:00] Debbie dB: theory of thinking stuff... it had to happen first.
[14:01] herman Bergson: Yes but then we are dealing with the history of Logic Debbie ^_^
[14:01] herman Bergson: For the next lecture I yet stick to the arabs and Aristotle :-))
[14:01] Debbie dB: yes ;) I forgot ... Ive been away too long.
[14:02] herman Bergson: So...thank you all for your participation again....
[14:02] .: Beertje :.: no Boolean algebra?
[14:02] Bejiita Imako:
[14:02] herman Bergson: Next lecture will tell you more about what the Arabs found in Aristotle and Plato
[14:02] Bejiita Imako: we can do computer programming another time after we are done with this subject
[14:02] Bejiita Imako: hehe
[14:02] Debbie dB: there are 10 types of people in the world - those who do binary and those who dont.
[14:03] .: Beertje :.: lol Bejiita
[14:03] herman Bergson: Bool was from the 19th century :-)
[14:03] Bejiita Imako:
[14:03] herman Bergson: Ahh ok Bejiita :-)
[14:03] herman Bergson: Class dismissed....
[14:04] Bejiita Imako: nice agai herman
[14:04] Debbie dB: thanks Herman - that was informative and fun.
[14:04] bergfrau Apfelbaum: ***** APPPPPPPLLLLAAAUUUSSSSEEEEEEE***********
[14:04] bergfrau Apfelbaum: APPPPPPPLLLLAAAUUUSSSSEEEEEEE ***** ***********
[14:04] herman Bergson: and for those who like it...start studying LSL :-))
[14:04] Bejiita Imako: YAY! (yay!)
[14:04] Debbie dB:  :**:. .:**:. .:* APPLAUSE!!! *:. .:**:. .:**:.
[14:04] Debbie dB:                      ¸. *´¨)     F*ckn Awesome!
[14:04] Debbie dB:             ¸. ´ ¸. *´¨) ¸. *´) ¸. *¨) ¸. *¨)
[14:04] Debbie dB:             (¸. ´ *(¸. ´ *(¸. ´ *(¸. ´ *(¸..
[14:04] Debbie dB:    Applause! «´·.¸¸.•.¸¸ YAY¸¸.•.¸¸.·`» Applause!
[14:04] bergfrau Apfelbaum: it was interesting to listen to you! thanks to all :o))
[14:04] Lizzy Pleides: Thank you herman, good night everyone!
[14:04] bergfrau Apfelbaum: babaLizzy:-)
[14:04] .: Beertje :.: Thank you Herman and Gute Nacht Lizzy
[14:04] Bejiita Imako: cu soon again
[14:04] Debbie dB: bye lizz, bejita,beertje bergie
[14:05] Debbie dB: and bye prof herman ;)
[14:05] herman Bergson: Bye Debbie :-)
[14:05] bergfrau Apfelbaum: bye bye ladys :o)) and mister professor see you next week:-)
[14:05] .: Beertje :.: bye bye goodnight

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