You are wandering a bit away from the target here, George.

>>You can live without religious faith, I suppose, but you cannot live without logic that structures not only rational propositions and arguments – uttered by “religious” as well as “irreligious” people<<

We agree on this, but I am not sure how it relates to what we are discussing.

Of course religious people are able to use logic, that is not in dispute. Nor is the fact that they are unable to use logic to reach a position that - logically - allows them to believe in God. We have already agreed that also.

So, am I to understand that you have finally worked out that yes, you agree also with my earlier statement that when the topic is "does God exist?", the use of faith and the use of logic are mutually exclusive.

For the sake of utter and complete clarity, I am not suggesting that a religious person only uses faith, and never logic. That would be strange indeed. But the same is not true of the empiricist, who will never mix the two.

And to make my position once again as clear as I possibly can. There is no path from an agreed premise - let us say, "the world exists" - to the existence of God, that allows a mix of faith and logic. The religionist can only start from the additional premise that "God exists", which can only, as we have previously agreed, be made on faith, not through logical deduction.

This does allow us to work through your other statement:

>>you cannot make “logical deduction from the things you know”: you can logically deduce only one STATEMENT from a set of other STATEMENTS in the sense that if you accept the truth of the set of “input” statements then logic forces you to accept the truth of the deduced “output” statement.<<

The deductions I make are from the statement "the world exists".

Which is actually something I "know">

Therefore I can, and do, make “logical deduction from the things I know”

Pericles, first of all I have to thank you for helping me to understand what you do not understand, and consequently also improving my understanding of the rationale behind my own world view.

“You are wandering a bit away from the target”
You might be right here; what I wanted to say was that one can discuss at lengths what faith is, and whether it is useful or not, whereas logic is a clearly defined and widely accepted concept, especially since it has been symbolised into mathematical logic, so there should not be much discussion about what it is.

Let me repeat: one of the factors that help you accept that God exists – beside cultural/educational prerequisites or “spiritual experience” – is a rational framework (usually called theology) which is logically structured. This you cannot deny, although you would not agree with its premises. “If all angels are immortal” and “John is mortal” then pure logic tells you that John is not an angel, irrespective of whether you believe in angles or not, but nothing more.

So logic helps you to rationally structure what you actually believe in but it cannot lead you to accepting or rejecting a world that your senses cannot provide a knowledge of. Neither can it lead you to a non-faith personal conclusion “a belief in God or a spiritual world is unnecessary for my life”, although you might have good reasons to feel like that. So logic and faith can coexist (logic structures the rational framework of your faith or “unfaith”) but logic on its own can lead you neither the one nor the other way, something like a program as clever as it might be, can do nothing for you without any input data. (ctd)

(ctd) Now it occurred to me, whether you do not equate faith with what is commonly known as spiritual or mystical experience. Well, you do not need logic to have such an experience, there I would agree with you. However many people who believe in God had never had such an experience (including myself) and many people who had such an experience reduce it to its neuroscientific demonstrations measurable by electrodes attached to their brains, and remain atheists or agnostics. So just having spiritual (mystical) experience should not be equated with religious faith.

I did anticipate a statement like “the world exists”, therefore I emphasized so much the need to know which terms are a priori identically defined by all involved. Assuming we know what “exists” means (philosophers discuss even that), then if by “world” you mean “material as well as spiritual world” then everybody will agree with you, full stop. If by world you mean only material world (i.e. everything that is accessible through senses) then everybody (except for solipsists) will also agree with you.

However, you cannot LOGICALLY deduce anything from a single proposition – the same with e.g. “God exists” - except for what I did in the example about two-handed humans, namely that “what does not exist is not the world”. If you have two propositions you can do a bit more, like the example with Kevin Rudd. From that example you could deduce that “the electorate prefers ALP to the Coalition”, however that is not a LOGICAL deduction on its own (you would have to add propositions about what is ALP etc.).

Let me repeat again: I can think of many rational (and irrational) arguments to support your empiricist’s belief that the origin of all knowledge is sense experience only. Call them deductions, if you like. Just please do not call them LOGICAL proofs or deductions.

It is a real shame you have reverted to wordplay, George.

If you continue to insist that no word can have an agreed meaning, then using words in order to have a discussion is in itself a pointless exercise.

But in an attempt to rescue just a notional amount of meaning from your post, I would like to point out the following:

>>one of the factors that help you accept that God exists... is a rational framework (usually called theology) which is logically structured. This you cannot deny, although you would not agree with its premises.<<

The word I have problems with in this sentence is "rational".

While theology has some consistency in its internal structure that bears some resemblance to logic, the prerequisite, as you point out, is a belief in a whole raft of irrational concepts such as angels.

So how can theology, that rests on a belief in irrational constructs, escape being irrational itself?

>>I can think of many rational (and irrational) arguments to support your empiricist’s belief that the origin of all knowledge is sense experience only. Call them deductions, if you like. Just please do not call them LOGICAL proofs or deductions.<<

If you recall, I entered this discussion in order to point out to goodthief that the definition of an empiricist is one who "regards experience as the only source of knowledge" - this is in fact the definition I found in the Oxford English Dictionary.

An empiricist, by definition, regards experience as the only source of knowledge. No "deductions" are necessary, logical or not, to reach this point.

It is a starting point, not a destination.

I know this doesn't mean anything to you, since your only starting-point is a belief in God. To rely upon knowledge, as opposed to belief, to get you through the day, is a foreign concept.

Pericles, I have to agree. There is really no point in trying to explain to you, or learn from you, anything. Fundamentalists are just like that: If they happen to believe in, say, the Christian God, they can only be happy if they know that only those who believe in God will go to heaven whereas those who do not will go to hell. If they happen to believe in something else which does not include a belief in God, they can only be happy if they know that only those who share their beliefs (or starting points or what) are logical, rational, scientific, etc. whereas those, including high ranking scientists, whose world view includes a belief in God are irrational, illogical, unscientific etc.

I do not want to, (and also cannot), deprive a religious fundamentalist of his/her simple-minded happiness, and the same applies to you. There are obviously no other readers following this thread to judge whether you or I have a better understanding of what logic is, or whether “knowledge, as opposed to belief is a foreign concept” for me.

So please just be happy in your empiricists beliefs, and forgive me for trying to communicate in a way which I thought was rational, an understanding somehow related to my life-long experience as a mathematician.

Of course, I meant to say "... whereas those, including SOME high ranking scientists, whose world view includes a belief in God..."