Any tips on where to begin? I've become extremely interested in the subject of logic thanks to the Austrian school. Problem is, I have *no clue* where to start. I need entry-level stuff because most of this is going to be self-taught.
I know there's the "stickied" praxeology thread but that's logic specifically in regards to the Austrian school.
There are a number of solid intro. to logic books.
H.W.B. Joseph's An Introduction to Logic is a really well-written exposition of traditional logic. It's loaded with footnotes, original Greek and Latin, and references to sources ancient, scholastic, modern. It's not an easy read, but it's worth going through slowly. It's probably my favorite.
David Gordon just used George Hayward Joyce's Principles of Logic for his class, I think. It's also a traditional book, but it's easier to read than the above and also comprehensive, and it has great references.
Mises recomended An Introduction to Logic and the Scientific Method by Morris R. Cohen and Ernest Nagel (I don't think this is available online; though, you may be able to find it on scribd; I'm not sure) to his students. It's also one of my favorites. It has good exercises, and the appendix is especially neat; it goes over some famous propisitions of Archimedes and Euclid and breaks them up and demonstrates how they are proved.
Jevons's two books Primer of Logic and Elementary Lessons of Logic are great for beginners. The former is really short and really will prime you for a more comprehensive reading of the other books mentioned. The latter reads like the books of Joyce and Joseph do, and I think it's actually now available at the Mises Store. Both books include questions and exercises.
I saved my Intro to Logic book from college -- I was a huge formal logic dork when I first encountered it (in college, unfortunately). It's a good one. I'll check the title when I get home.
A List Of Fallacious Arguments
http://www.don-lindsay-archive.org/skeptic/arguments.html
I also recommend you take a look at a computer logic book since seeing how logic can be physically realized (in mechanical or electrical systems) is helpful in visualizing what is going on. Even more important, I think it helps you avoid attaching any sort of mystical awe to logic, which I feel sometimes the more metaphysical approach can lapse into. DeMorgan's theorem is pretty much the most advanced logic concept you need and the explanation you will find in a computer logic book is very straightforward and practical... in a metaphysical logic book, I've seen a lot of unnecessary verbiage and over-gushing adulation of the theorem as if it were the handiwork of God Himself.
In other words, get good at Boolean algebra... the rest is just warm and fuzzies.
Clayton -
First figure out what you even mean by the word logic. If you weren't a grand master of deductive reasoning already, you'd be dead by now. The only reason deduction is ever hard is because words get in the way. The problem is that people are imprecise with words. Once you have precision, logic becomes a simple matter of noting the structure of your mental pictures.
Studying logic would be purely a waste of time if it weren't for the fact that it makes you do a bunch of exercises where you're forced to notice how to be more precise in your expression and interpretation of words. Aside from whatever value you might get from knowing the common logical terms and symbols, you can end-run the whole study just by being a stickler about definitions.
Why anarchy fails
Wow thanks guys, this is basically what I'm looking for.
And what I mean by logic is...well...just the field involving (how to avoid) fallacies, a priori, empiricism, stuff...see I know what I mean but I can't really explain it.
Thanks for the reminder of not to get too mystified by logic, I fear I may have actually been doing so.
Aside from whatever value you might get from knowing the common logical terms and symbols, you can end-run the whole study just by being a stickler about definitions.
I don't mean to strawman or misinterpret, but are you saying that definitions are basically good enough? (Like searching the definition for a priori.) Because I've actually been doing that up to this point and so far it seems to have worked out alright.
Reading about it and being useful in practice are different ducks. You must make a habit of approaching every problem with a method. Otherwise you are just another nirvana critic. There is an undersupply of engineering technique.
I'm surprised no one has linked to the Mises Academy courses yet.
David Gordon just finished teaching a round of How to Think: An Introduction to Logic and his next class How to Know: The Epistemology of Ludwig von Mises is actually about to start on April 7.
im_retarded: Aside from whatever value you might get from knowing the common logical terms and symbols, you can end-run the whole study just by being a stickler about definitions. I don't mean to strawman or misinterpret, but are you saying that definitions are basically good enough? (Like searching the definition for a priori.) Because I've actually been doing that up to this point and so far it seems to have worked out alright.
Not "searching a definition for a priori," as there is nothing in a definition besides some words designed to get other people to see what you are referring to. I just mean, if you are completely clear with your definitions and wording and insist that other people be clear with theirs and stick to them (every key word that makes or breaks their argument), logic will take care of itself by the natural reasoning ability you already use successfully for everything else in life.
Here's the book I mentioned:
Copi and Cohen's Intro to Logic, 10th edition
They have later editions, which may or may not be better, here.
AJ: Not "searching a definition for a priori," as there is nothing in a definition besides some words designed to get other people to see what you are referring to. I just mean, if you are completely clear with your definitions and wording and insist that other people be clear with theirs and stick to them (every key word that makes or breaks their argument), logic will take care of itself by the natural reasoning ability you already use successfully for everything else in life.
Even if you are right about logic, that's like saying that we don't need to understand linguistics because we don't need it to speak, we just need our natural language ability. But in studying linguistics there is a lot to learn about that natural language ability, and in studying logic there is a lot to learn about what makes a valid argument and so on.
I'd say look at this first. Feel free to ask me any questions.
The keyboard is mightier than the gun.
Non parit potestas ipsius auctoritatem.
Voluntaryism Forum
Chris_Bacon: AJ: Not "searching a definition for a priori," as there is nothing in a definition besides some words designed to get other people to see what you are referring to. I just mean, if you are completely clear with your definitions and wording and insist that other people be clear with theirs and stick to them (every key word that makes or breaks their argument), logic will take care of itself by the natural reasoning ability you already use successfully for everything else in life. Even if you are right about logic, that's like saying that we don't need to understand linguistics because we don't need it to speak, we just need our natural language ability. But in studying linguistics there is a lot to learn about that natural language ability, and in studying logic there is a lot to learn about what makes a valid argument and so on.
As I mentioned above, if there is any value in studying "logic," it is that the exercises and examples and law force you to notice how tricky words can be. People have no trouble understanding what makes a valid deduction when words aren't getting in the way. If they did, they'd fail at every mental task they attempted. Understanding word-based errors and the praxeology of communication are where the action is, not so-called "logic."
Autolykos: I'd say look at this [http://en.wikipedia.org/wiki/Law_of_thought] first.
I'd say look at this [http://en.wikipedia.org/wiki/Law_of_thought] first.
The whole Laws of Thought approach is kind of a pet peeve of mine. There is nothing wrong with it per se, but it makes it look like there are some authoritative laws that need to be followed for some philosophical reason, when really all they are are ways to prohibit (via a sort of philosophical intimidation) certain common verbal misunderstandings of people's utterances. I propose actually looking at the source of the problem: how and why words can be so confusing.
AJ:The whole Laws of Thought approach is kind of a pet peeve of mine. There is nothing wrong with it per se, but it makes it look like there are some authoritative laws that need to be followed for some philosophical reason, when really all they are are ways to prohibit (via a sort of philosophical intimidation) certain common verbal misunderstandings of people's utterances. I propose actually looking at the source of the problem: how and why words can be so confusing.
I don't get that meaning from the Laws of Thought at all. To me, the Laws of Thought are about non-contradiction.
The nature of words is something of a different story IMO. Words can be so confusing because they're not bound to certain definitions. At all times, people are free to use whatever meanings for whatever words that they want to use.
Words are not bound to certain definitions, but people have a tendency to cling to their own definitions when discussing things as if everyone else really means the same thing when they say the same word. Even though they know (if you point it out) that other people have different definitions, they seem to compartmentalize that knowledge so they are temporarily blind to it during a debate. Something in them wants the word to mean the same thing to everyone, or feels it really objectively should have the same meaning to everyone.
I sometimes have called it the phenomenon of "sticky definitions." You can feel the definitional the stickiness in every debate on these forums. It's visibible in the slightly longer (and sometimes much longer) time people take to adjust the tenor of their responses, compared to how fast they would adjust if they had been fully aware of the possibility of other people using different definitions.
But the elephant in the room when it comes to all thinking and intellectual discussion is something called word-thought overwriting, which I mentioned briefly elsewhere but hope to explain in greater depth in future posts. If I could eliminate just one thing from everyone's thought process, and from my own, it would be word-thought overwriting.
AJ, you're definitely right that (some) people have that tendency. I think they have that tendency because they simply lack the mental discipline to use definitions that are different from the ones they're used to, and/or (worse IMO) they actually aren't concerned with the validity of the arguments presented per se - they're concerned with looking like they're "winning" (i.e. in the "stronger" position). All the emotional grandstanding you see in debates, both online and offline, have to do with that latter reason.
That's all true as well. One thing, though: I'm not sure there is anyone who is totally fluid with their definitions. I remember when you wrote in another thread something like, "By certain definitions of exist, you don't exist." There's still a little shock when the reader sees that, I think, even if they are aware of this, and even though - obviously - those other definitions could be anything at all. In the very next sentence you could have continued, "For example, if exist is defined as 'weigh 500kg' then you don't exist." The reader knows that, but it still hits him a bit. It still hits me for a brief moment, but I just make sure to adjust for it before I reply. Recognizing the effect is probably enough a lot of the time.
I think an important underlying reason is there is a social pressure to respect the authority of words. Words are supposed to be able to do things in society. Some words can seal a marriage. Merely uttering some words could get you arrested. And even just the fact that other people react strongly to words - even if you originally don't - is enough to make everyone react strongly to them, because we're social animals. And think of words like love, duty, honor, sin, etc. They are each part of their own set of social relations and pressures that bear down on every person in society.
The thing is, what authority do words (i.e. sound-forms) have on their own? None. It's the semantics (the mapping of meanings to sound-forms) that have authority, by virtue (so to speak) of their common agreement. On the other hand, one is never bound prima facie to follow or even respect that semantic authority. He is, at all times, free to use different meanings for the same words. What I would consider dishonest (if not fraudulent) is if he does so without communicating it to those with whom he converses.
I'll second the reccommendation for Jevons' Elementary Lessons.
AJ:As I mentioned above, if there is any value in studying "logic," it is that the exercises and examples and law force you to notice how tricky words can be. People have no trouble understanding what makes a valid deduction when words aren't getting in the way. If they did, they'd fail at every mental task they attempted. Understanding word-based errors and the praxeology of communication are where the action is, not so-called "logic."
I have ten books, and I don't have ten books / Therefore, I am Nietzsche.
I assume you understand the meaning of everyword in that argument, so is it deductively valid or not?
Logic extends far beyond what makes an argument deductively valid, it even rears its head in linguistics amongst various other disciplines. Studying it for those reasons is not as you say, 'the exercises and examples and law force you to notice how tricky words can be'. Also, it is only through the study of logic that we have made certain philosophical breakthroughs.
I suspect you are wrong about, 'People have no trouble understanding what makes a valid deduction when words aren't getting in the way.'
Autolykos: The thing is, what authority do words (i.e. sound-forms) have on their own? None. It's the semantics (the mapping of meanings to sound-forms) that have authority, by virtue (so to speak) of their common agreement. On the other hand, one is never bound prima facie to follow or even respect that semantic authority. He is, at all times, free to use different meanings for the same words. What I would consider dishonest (if not fraudulent) is if he does so without communicating it to those with whom he converses.
I fully agree with what I think your point is, but while there is no real authority to words, there is part of us that acts - even momentarily - as if they do mean what we first assume them to mean. That is the definitional stickiness. So it is not always dishonest when someone uses a different meaning. In fact, mostly it seems accidental. People just forget...because of the stickiness. Any preconceived notions or biases or ire will of course further delay their realization of what is going on - sometimes forever.
Even in the thread about bullying, it seems that one group of posters are using it to mean intimidation and teasing without violence, whereas another group is using the word to include violence. So they appear to hotly disagree for while, until they see what is going on. In that case, for example, it seems unintentional. Indeed, the word bullying is sometimes used to imply violence but other times it is used without referring to any actual violence, so it is ripe for this kind of problem.
Chris_Bacon: AJ:As I mentioned above, if there is any value in studying "logic," it is that the exercises and examples and law force you to notice how tricky words can be. People have no trouble understanding what makes a valid deduction when words aren't getting in the way. If they did, they'd fail at every mental task they attempted. Understanding word-based errors and the praxeology of communication are where the action is, not so-called "logic." I have ten books, and I don't have ten books / Therefore, I am Nietzsche. I assume you understand the meaning of everyword in that argument, so is it deductively valid or not?
It is not an meaningful statement. Or if it is, then I don't understand at least one of the words in it, because there is no usual meaning I can assign to the word "have" (for example) that makes the statement "I have ten books, and I don't have ten books" make sense. It is gibberish to me. Whoever utters it has not managed to communicate their thoughts to me, so there is no argument for me to evaluate.
Other disciplines may use the word "logic" but often it is in a different sense, e.g. circuit logic, but my comments in this thread are limited to the idea of learning logic in order to figure out how to argue better and reason better. For that, I suggest instead learning about the praxeology of communication, as that is where the action is.
AJ, I didn't mean to imply that I disagreed with you about "definitional stickiness". I certainly do agree that it happens to people. You're right, too, that a person falling prey to it isn't being intentionally dishonest. In such a case, though, he's not consciously choosing to implicitly use a definition which he knows (or has strong reason to expect) is substantially different from that which other people use - which is what I was talking about.
I'm fond of pointing out differences in definitions to people during debates. You'd be surprised (or maybe you wouldn't be) at how many people react with hostility. They often start to claim that their definitions are the "right" ones. In my opinion, they either lack sufficient self-awareness to realize otherwise, or they're still trying to "win" the debate somehow. Neither of these sits well with me, of course.
AJ: It is not an meaningful statement. Or if it is, then I don't understand at least one of the words in it, because there is no usual meaning I can assign to the word "have" (for example) that makes the statement "I have ten books, and I don't have ten books" make sense. It is gibberish to me. Whoever utters it has not managed to communicate their thoughts to me, so there is no argument for me to evaluate. Other disciplines may use the word "logic" but often it is in a different sense, e.g. circuit logic, but my comments in this thread are limited to the idea of learning logic in order to figure out how to argue better and reason better. For that, I suggest instead learning about the praxeology of communication, as that is where the action is.
Then you don't understand the basics of propositional logic. I was asking if the argument was valid; it can be expressed in the following form, if turned into a conditional:
(B ∧ ¬ B → N)
It is a valid argument, but I'll let you figure out why. So perhaps you better get back to studying some more logic, before you try to argue that if, 'there is any value in studying "logic," it is that the exercises and examples and law force you to notice how tricky words can be.'
Chris_Bacon: Then you don't understand the basics of propositional logic. I was asking if the argument was valid; it can be expressed in the following form, if turned into a conditional: (B ∧ ¬ B → N) It is a valid argument, but I'll let you figure out why. So perhaps you better get back to studying some more logic, before you try to argue that if, 'there is any value in studying "logic," it is that the exercises and examples and law force you to notice how tricky words can be.'
I am well aware of the principle of explosion, but as I said I find the system in your textbook (and its terminology) superfluous. I never said it was not a "valid argument" in propositional logic; my point is that that terminology is un-elucidating, and it is more elucidating and cleaner to phrase things my way. Here is why:
Do you know why that is considered a logically valid argument in formal logic? Because if you have contradictory premises you can "prove" anything (principle of explosion), the practical application for becoming an effective reasoner being: don't trust conclusions - no matter how wild - if there are any contradictions in your premises.
Notice that what I said, "the statement is meaningless," results in the exact same conclusion, except that my way is cleaner and more efficient. Start with meaningless premises, and there is no argument at all. That is my way. Your textbook's way is to say that it is an argument, but absolutely anything you put for the conclusion will still be "valid." This results in a "wowee-zowee" result, but I see that as a weakness, because nothing too interesting is actually happening. Nonsense is being spoken, therefore no argument is being conveyed from the mind of the speaker to the mind of the listener. Your textbook considers statements as if they are free-floating, independent of expressing the content of any person's thoughts.
My approach treats statements as attempts to convey thoughts or other experiences. Hence the different phrasing. My approach brings the focus to where the real action is, and where the real insidious errors are made (including all "logical errors"): the very nature of words and communication.
As far as learning how to reason, rules like the formal logical principle of explosion tell you nothing about the underlying communication situation, and therefore do nothing to shield the learner against reification and other quite illogical things. "Oooh wow, contradiction lets me prove anything, how mysterious" may be more fun, but "you're not communicating anything to me, bro" is closer to what is actually happening, and I contend far less likely to lead to error in thinking - which is the whole point in the first place.
Autolykos:I'm fond of pointing out differences in definitions to people during debates. You'd be surprised (or maybe you wouldn't be) at how many people react with hostility. They often start to claim that their definitions are the "right" ones. In my opinion, they either lack sufficient self-awareness to realize otherwise, or they're still trying to "win" the debate somehow. Neither of these sits well with me, of course.
Yeah, this is a weird phenomenon, and I do that a lot, too (point out differences in definitions), and it irritates people sometimes. So most people refrain from pointing it out too much, like it's taboo or something, but I don't refrain, because it very often is the key to the whole debate. And even if it is not the big key, the debate certainly cannot even start until people agree on definitions. But it's like deja vu, where the discussants at some point a few pages into the thread finally realize they had different definitions and resolve things, but then in the next thread it happens again with a different set of key words, and they go through the same process, thread after thread. It seems to take many exposures for most people to see the pattern, to the point where they finally learn to stay on the lookout for definitional differences from the very beginning.
The most insane thing is that if you point out semantic issues like this, people will often accuse you of "arguing semantics," which is actually exactly what you're trying to point out that they are doing! It's yet another equivocation: "arguing semantics"=manipulating semantics to try to make a false argument look right (what they're doing), vs. "arguing semantics"=making points about the semantics of the argument (what you're doing). What a mess it becomes, when you point out an equivocation, they are blinded from seeing it by another equivocation.
Side thought: Someone said something like, "Label me, and you delete me." It's like people don't want to part with their pet definitions, because by giving something a label they can put it in a box and feel like it's a known quantity, not as scary, etc. Maybe people get irritated because you threaten to take that away from them when you remind them that definitions are arbitrary (OK, not quite totally arbitrary, but only non-arbitrary in the sense that a certain definition might be really common).
AJ: Do you know why that is considered a logically valid argument in formal logic? Because if you have contradictory premises you can "prove" anything (principle of explosion), the practical application for becoming an effective reasoner being: don't trust conclusions - no matter how wild - if there are any contradictions in your premises.
The reason it is deductively valid is because there is no case in which the conclusion can be false with the premises being true - because the set of premises can never be true; therefore, 'if you have contradictory premises you can "prove" anything (principle of explosion)'
AJ:Notice that what I said, "the statement is meaningless," results in the exact same conclusion, except that my way is cleaner and more efficient. Start with meaningless premises, and there is no argument at all. That is my way. Your textbook's way is to say that it is an argument, but absolutely anything you put for the conclusion will still be "valid." This results in a "wowee-zowee" result, but I see that as a weakness, because nothing too interesting is actually happening. Nonsense is being spoken, therefore no argument is being conveyed from the mind of the speaker to the mind of the listener. Your textbook considers statements as if they are free-floating, independent of expressing the content of any person's thoughts.
Meaning isn't objective. And what an argument is, isn't determined by its meaningfulness. Instead a set of sentences is an argument solely if it consists of a/some premise/s and a conclusion.
AJ:As far as learning how to reason, rules like the formal logical principle of explosion tell you nothing about the underlying communication situation, and therefore do nothing to shield the learner against reification and other quite illogical things. "Oooh wow, contradiction lets me prove anything, how mysterious" may be more fun, but "you're not communicating anything to me, bro" is closer to what is actually happening, and I contend far less likely to lead to error in thinking - which is the whole point in the first place.
Logic isn't restricted to the principle of explosion. You seem to be confusing validity and soundness. An argument taking the form of the principle of explosion can never be sound, because the set of premises will never be true - unless you include contradition into a new logic - but it is still a valid form. It is logical form that logic is concerned with, not soundness.
Chris_Bacon:Meaning isn't objective.
Yes, that's it exactly. Meaning isn't objective. Or better to avoid the word meaning and use the words intention and interpretation. By calling the string of words "meaningless" I mean I find no coherent way to interpret it into a thought in my mind. If one cannot interpret a string of words, one cannot even begin to evaluate it as an argument. (Yes, I know in propositional logic they let you do that; that is part and parcel of the whole system I find useless at best.)
Chris_Bacon:Logic isn't restricted to the principle of explosion. You seem to be confusing validity and soundness. An argument taking the form of the principle of explosion can never be sound, because the set of premises will never be true - unless you include contradition into a new logic - but it is still a valid form. It is logical form that logic is concerned with, not soundness.
Soundness, validity, etc. - it's not useful terminology to me, so I may differ from your textbook from time to time.
In fact, all of propositional logic rests on a questionable foundation, for a reason you already seem to grasp: The meaning interpretation of a statement is not objective. Propositions (words) are not truth-apt until they are interpreted into thoughts. Propositional logic treats a sentence without considering the thought in the speaker that prompted it, and without considering how the listener interprets it - which are the only two things that matter for argumentation, conveying a theory, or any intellectual discourse.
It seems to me that what I am trying to do in intellectual discourse is this:
(1) I have a thought, and I would like to get other people to experience that same thought. Since we're not telepathic, I am usually forced to (2) put the thought into words in hopes that other people will (3) interpret it into a thought that matches mine. It looks pretty simple: unless all three steps happen in order, it doesn't seem useful to call it intellectual discourse, or an argument, or the conveying of a theory.
With that in mind, it might be easier to see why I say that if a proposition has a contradiction that prevents the listener from being able to interpret it, communication/discourse/argument simply has not happened yet. Steps 1 and 2 may have happened, but Step 3 hasn't.
Now in the case of contradictions, there is question that comes even before that: What was the speaker thinking before he or she uttered the contradictory proposition? What was the initial thought (Step 1)? If it is truly impossible think a bona fide logical contradiction (not just the words, but the actual thought behind them), then the communication can't even have started (Step 1 has been skipped), and the words hardly seem worth calling a "proposition" at all.
So when someone utters an apparent contradiction, the best idea would be ask the person to clarify. If they refuse, ask what they are even trying to do. Are they trying to get a thought from their mind into yours, or are they just making noises for some other reason?
This might seem mundane, but in fact there are many people who will try to espouse a theory while telling you flatly that they do not understand it, can't visualize it, or that it has unthinkable elements in it. This means they are not communicating (they just told you Step 1 is impossible!), but rather they think the theory is sitting there in some kind of objective meaning in the words themselves. Those who speak of 4 or more spacial dimensions come to mind. Propositional logic can't tell you how 11D space is a bogus idea, but the praxeology of communication can. I recommend it because it is both simpler and more broadly applicable than propositional logic. Plus it helps reveal word-based error, which propositional logic does not. Propositional logic won't even catch equivocations or WTOs (in fact it renders them invisible), which are the real culprits in most fuzzy-headed thinking and so-called logical errors.
AJ: The most insane thing is that if you point out semantic issues like this, people will often accuse you of "arguing semantics," which is actually exactly what you're trying to point out that they are doing! It's yet another equivocation: "arguing semantics"=manipulating semantics to try to make a false argument look right (what they're doing), vs. "arguing semantics"=making points about the semantics of the argument (what you're doing). What a mess it becomes, when you point out an equivocation, they are blinded from seeing it by another equivocation.
OMG. Though I probably agree with Selgin, he just did this!
Though I am not sure who is right, no he didn't. He merely explained very clearly why the debate is not about semantics. And made a claim that his opponents are trying to win their argument by defining it into correctness.
My humble blog
It's easy to refute an argument if you first misrepresent it. William Keizer
If Selgin's opponents are trying to define their position into correctness, the debate is (currently, at least) about semantics. Selgin's equivocation seems to be keeping him from seeing that when your opponent makes a semantic argument as evasion, the solution is to point that out, and refuse to continue making points until definitions are agreed upon.