What use is formal logic to philosophy?

Stephen asked:

Greetings Philosopher-Kings! My question to you is of a practical nature but I feel would fall outside of the Problem Removal Service. I am only beginning my self studies in the field of philosophy and have been groping around to find the most efficient path to becoming relatively well-versed in philosophy. What I respect the most about the study of philosophy is the ability of the philosophers I have met or read to quickly and clearly identify the flaws in the premise or structure of an argument. I have assumed this was due to their background in formal logic.

My question then is ‘How integral is Logic or Advanced Logic to the study of philosophy as a whole, and is it simply useful in some fields such as philosophy of language or mathematics, and not in others, such as ethics or political philosophy where perhaps only a basic understanding of argumentation theory would be necessary. Moving forward in the study of philosophy (and any of the other common fields in academia for that matter) would the study of Logic be very beneficial?

(If you are feeling generous, some names of a few good books to get started in the field would be a great help.)

Answer by Craig Skinner

I’m no philosopher-king, actual or potential, but having reached the end of the beginning (recent distance-learning BA Philosophy with Pathways support), maybe I can help you as an acknowledged beginner.

You say you are ‘groping around to find the most efficient path’. In my view, there is no substitute for hard work, and it needs to be focussed, interactive and challenged. Best is to sign up for some qualification (diploma, degree, Pathways modules all suitable). Self-study alone, although educational and fun, tends to be diffuse and unrigorous. You need to be writing essays which are critically appraised by somebody further along the road, and aiming to pass exams or submit a dissertation within a definite time frame.

What about formal logic?

There is no need for fluency in the formal languages of logic in order to study and understand philosophy. The 2010 study guide for the London BA (Phil) says in its blurb about the compulsory Philosophical Logic module ‘Formal logic does not figure as such in the examination…., but some knowledge of elementary formal logic is necessary for the subject as a whole’. It then goes on to recommend a book offering a ‘gentle introduction’ to formal logic (more from me below).

I got excellent marks in my Philosophy of Mathematics, Philosophy of Science and Philosophical Logic modules with no more knowledge of formal logic than a ‘gentle introduction’.

As a student of philosophy your focus will be analysis of and reflection on concepts arising out of/built into logic and reasoning – deduction, induction, abduction, validity, identity, necessity, truth, reference, definite descriptions, conditionals. In addition you may wish to reflect on the reasons for the existence and the value of non-standard logics which deny bivalence or deny Aristotle’s laws such as LEM or even LNC. Also a basic understanding of nonbivalent, including fuzzy, logic, is needed to understand the concept of vagueness.

In addition you will be familiar with notions that long predate formal logic, such as circular argument, begging the question, equivocation, reductio ad absurdum.

I think too much 20th Century analytic philosophy writing was infected by logical symbolism, but the heyday of this has passed and philosophical logic is re-emerging with new vigour after decades of debility due to that infection. The love affair between analytic philosophy and logical symbolism blossomed with publication in 1905 of the Theory of Descriptions in Russell’s ‘On Denoting’ (that ‘paradigm of philosophy’ as Ramsey called it in 1931). Russell was seen as ushering in a new age of rigour – many old philosophical problems would simply be shown up as confusions of thought; woolly Continental metaphysics was exposed; Meinong’s alleged nonsense about nonexistent objects was supposedly rebutted. And indeed it was a shot in the arm to philosophy, although our view of it is more nuanced these days, and logical analysis of language delivered less than was hoped for. But, at any rate, Russell couched his theory in the symbolism of his (and Whitehead’s) Principia Mathematica, starting the trend of discussing such matters in terms of symbolism when they can be understood without it (of course it is true that some people find it easier to grasp ideas symbolically).

As for the gentle introductory text, I have the main contenders on my bookshelves, including Hodges, Newton-Smith and Guttenplan, and have read them. They are all more than adequate. I think the best is Guttenplan:

Guttenplan S (1997) The Languages of Logic; an introduction to formal logic, 2nd ed., Blackwell

All the best with your studies.

 

Why were my comments deleted?

Robert asked:

I see that your moderators pull many comments. The few comments that make it through the ‘gauntlet of censorship’ disappear at month’s end via a full comment board wash. My philosophical question is what is the REAL, GENUINE, TRUTHFUL purpose of these actions? I personally often find that comments are more insightful than the questions, stories or philosopher responses. What place does moderation or censorship have in philosophy? Please send a genuine and truthful answer as I would expect nothing less from genuine philosophers.

Answer by Shaun Williamson

Robert this is a site where people can ask questions about philosophy. They can also comment on questions that other people have asked. What they cannot do is use the site to expound or publish their own philosophical ideas. That is what you have been trying to do Your comments are not relevant to the questions you are commenting on.

You are not being censored, your comments are being removed because they are not RELEVANT to the questions you are commenting on. Don’t try to use the site to publish your own philosophical ideas. Go and write a book or an essay. If you wish to ask a question then ask a question.

Do not use this site to try to publish your own ideas, that is not what this site is for.

 

Answer by Peter Jones

Hello Robert. This post of yours and others that have not appeared are the reason that this site needs to be moderated. That is, it is posts such as yours that create the need for moderation. They are muddled, opinionated, immoderate, dogmatic and completely out of place in a philosophical discussion. If you cannot see this then perhaps you could try taking an online or college philosophy course and seeing how you get on.

 

Answer by Stuart Burns

Having read a number of your posts to this forum, I regret to inform you that I agree with the Moderator in ‘censoring’ your contributions (or at least those contributions I have read so far).

Your posts simply expound a particular view without offering any argument, or philosophical basis, for your position. Nor do they appear to address the questions for which your posts are supposed to be an answer. Your comments are offered in the manner of ‘received wisdom’ – offering no possibility that they might be in error in some fashion. They do not offer anything that any other philosopher who might disagree with you, can come to grips with. In other words, I can find no place to suggest where you might have made an error in fact or logic. I can only disagree with you – hardly a propitious beginning for a philosophical discussion, and more akin to theological debates.

Consider your post above. You seem not to understand the purpose and function of the ‘Ask a Philosopher’ web site. It is not a general forum for free posting of ‘comments’. It is designed (and, yes, moderated) to be a forum for philosophical responses to philosophical questions. The answers posted are intended to be reasoned responses, frequently drawing on the large history of writings of well known philosophers.

The questions that I choose to answer, as just one of the contributors, are those questions that tweak my interest as offering some interesting aspect on a philosophical issue. I am sure that other contributors have other criteria for questions that initiate their own responses. So if you would like your contributions to ‘make it through’ the moderation and censorship, you might like to try composing a more pointed philosophical response to some question, instead of simply commenting on the general area of the question.

While you personally may often find that comments are more insightful than questions or philosophical responses, please keep in mind that this web site is not intended for ‘comments’. It is the philosophical nature of the question and response that are the intended format of the service. Perhaps you may find a more suitable venue for your comments on one of the many philosophical forums on the web. I can start you off by suggesting http://onlinephilosophyclub.com/forums/.

 

Answer by Geoffrey Klempner

As the sole moderator for Ask a Philosopher I take full responsibility for all decisions to include or exclude comments posted on answers provided by the Ask a Philosopher panel members. I am also responsible for choosing which of the answers submitted by panel members to publish on the Ask a Philosopher pages.

I do not enter into personal correspondence over particular issues of moderation with visitors to the site. However, I felt that it would be valuable in this instance to air the matter here.

In this case, I felt that my moderation needed to be moderated, so I showed the deleted comments to members of the panel and asked for their views. Those who expressed an opinion, said that they fully agreed with my decision. If they had disagreed, then we would have debated it.

The bar is in face set rather low. We do not exclude comments because they are insufficiently intelligent, or because we think they are misguided, or based on a misunderstanding of the question or the answer, or just plain wrong. One learns from other people’s errors. Apart from spammers, very few comments are deleted. But Robert’s comments on this occasion were below the bar.

Robert is welcome to continue submitting questions and comments. However, if he doesn’t like the way Ask a Philosopher is moderated then I would advise that he looks elsewhere for forums where he can freely express his opinions without fear of being ‘censored’.

 

What do we want from answers?

Steve asked:

What do we want from answers?

Answer by Eric George

What is given to us by answers and to which what we as human beings desire from answers, is of course; truth. Herein however, lays before us an even deeper question – ‘But what is truth?’ Truth, it could be said, is what is ultimately correct and objective (and therefore by nature not subjective).

By objectivity (that which is ‘objective’) we mean a fact concerning something which is completely autonomous of personal opinion, in other words – something concerning given reality which is or would be true whether one person in the world or no one in the world believes it to be true or not. And of course this follows that by subjectivity (that which is ‘subjective’) we mean to be an opinion based belief, this belief being true or not has nothing necessarily to do with someone believing that particular belief.

For example, suppose there exists a room of ten people where nine of the ten people do not believe the existence of gravity to be true (despite them all not floating around in mid-air), the tenth person however does indeed believe in the existence of gravity to be real. Now, just because the majority of persons in the room hold a belief which denies the existence of gravity does not mean at all that they are correct – on the contrary, in this scenario, it is the minority of one person who holds the belief that gravity is objectively true, that is correct.

So answers naturally follow questions (or at least try to ‘catch’ questions upon following), and questions are formulated by human beings who wish to interpret or unveil reality for what it really is, to explain what essentially is. In that, logic and rationality were not invented subjectively, they were discovered objectively as the blueprints of explanation, discourse and understanding.

We ask questions about reality and all that it encompasses in order to ascertain truth by answers to these questions. Now, permit me to clarify something here, of course just like most things in life not everything is so ‘black & white’, especially when dealing with the very nature ‘answers’. That is, not all answers are true since an answer to a question or inquiry could very well be false, so opinionated answers although they could be true (an opinion based upon objective truth is merely an extension of the fact itself, rather than a deviation from it) are probably more often than not, simply untrue.

Because for all opinionated answers to be true, this would mean that every or any single opinion held by any person in the world could all be true at the same time, which would going back to our scenario, make all ten people correct despite the nine being objectively wrong. Truth therefore, by definition is exclusive – and answers which seek to fulfil corresponding questions must be objectively true, wholly apart from opinion and totally binding across all planes irrespective of cultural or social conditions.

 

Which of these statements did Plato hold?

Jenny asked:

All of the following statements pertain to Platonic philosophy EXCEPT

1. the road to knowledge goes through the Socratic dialectic
2. one arrives at knowledge through sense experience
3. the Good is the highest Form
4. the world of opinion is not to be trusted

Answer by Peter Jones

Hello Jenny.

Okay. I will do your test for you.

All philosophical statements pertain to Platonic philosophy. It is the whole idea of philosophy that all statements should pertain to each other. I presume you (or whoever set your test paper) meant something other than ‘pertain’.

You may have some difficulty in establishing exactly what the phrase ‘Platonic philosophy’ means, and it may depend on who you ask. I doubt, however, that Plato or any other philosopher in their right mind would endorse all of these statements. The first is false, since a dialectic intellectual process produces good and bad theories, not knowledge. The second is false for well-known Cartesian reasons. The third sounds a rather like Plato, but I do not know exactly what it means and neither do you. The last one is a tautology. On the whole, therefore, I would say it hardly matters what Plato would have thought about these statements. What you think about them would be much more important.

 

Answer by Geoffrey Klempner

Your teacher expects you to say that the answer is 2. If that’s all you wanted to know then you don’t need to read any further.

He/ she wants you to say this because in the Republic (analogy of the Line) Plato says that sense experience cannot give episteme (translated as ‘knowledge’) but only doxa (translated as ‘opinion’).

How do we know that we mean the same thing by ‘knowledge’ that Plato meant? That’s one question you could ask your teacher.

Another question you could ask is why, if ‘the road to knowledge goes through the Socratic dialectic’, all of the Socratic dialogues end inconclusively, not with ‘knowledge’ but with the admission that we don’t know what virtue, or courage, or temperance or etc. are – but at least now we know that we don’t know. How does that help?

Is the Good the highest Form? Plato describes it as the ‘light’ by means of which our minds are able to perceive the Forms (story of the Cave). That would seem to make the Good something rather different from ‘just’ being the highest Form. The light by means of which I perceive one particular mountain to be the highest mountain isn’t a mountain. It isn’t the same kind of thing.

Some opinions are true. Even Plato acknowledged that. Someone who seriously made the attempt ‘not to trust’ any of his/ her opinions would be in a very sorry state (this is in effect Pyrrhonian scepticism). Plato recognized that as long as we have to get around the world (for example, find the road to Larissa, Meno) we have an interest in distinguishing trustworthy beliefs from untrustworthy guesses.

 

Kant on why one should not make a false promise

Sam asked:

What is the reasoning by which the first formulation of Kant’s categorical imperative supposedly disallows making a false promise?

Answer by Martin Jenkins

In his Grounding for the Metaphysics of Morality [1785], Immanuel Kant introduces and elaborates the morality of the Categorical Imperative. He provides various examples such as the one concerning Promising.

A person is in financial difficulty and needs money. S/he hopes to acquire the money by borrowing it on the basis of a promise to pay it back. S/he has no intention of paying it back. What is the morality of this? Is it right or wrong? Responses may be that ‘You ought to repay it as no-one will believe you in the future and you won’t be loaned money when you might need it.’ In other words, the motive for keeping the promise is self-interest. Yet this approach could hide many ulterior motives – not any that could be objectively and compellingly good.

If based on self-interest, all the person is really concerned about is him/herself, not the person who loans the money nor the rightness or wrongness of keeping/not keeping the promise. Perhaps the person wants to keep the promise for now so s/he can borrow an even larger sum in the future and then renege on the promise. S/he will honour the promise not because s/he believes in the act of promising; s/he keeps the promise as s/he wants to enhance their reputation as an upstanding citizen. S/he might repay the debt as the lender is a close friend who s/he does not want to offend out of affection. S/he might keep the promise out of love for their kneecaps – fear of failing to repay the debt – and not out of respect for the act and nature of promising.

It is objections like these that makes Kant dissatisfied with existing morality. Promising is kept not because it is right to keep it but, on the grounds of extraneous motives, inclinations, desires or perceived consequences. He terms this approach that of Hypothetical Imperatives. As Jean-Paul Sartre noted – the road to hell is paved with good intentions. Likewise, any means can justify the good ends or consequences.

To avoid the Hypothetical Imperative based on motives and consequences, there needs to be an objective principle or criteria by which the thinking being can decide upon right or wrong courses of action and, which is thereby free from the grounds of motivation, empirical consequences and passions. Courses of action are decided by the Will dutifully adhering to a law. This law is ‘I am never to act otherwise than so I could also will my maxim should become a universal law’. Right or wrong is dependent upon Reason deciding whether the maxim could be universalised or not. Note that it is not about acting from motives, feelings or perceived consequences be they good or bad. So with having the intention of making a promising and failing to keep it Kant responds:

“How would it be if my maxim were a universal law? Then I see at once that it could never hold as a universal law of nature but would necessarily contradict itself. For suppose it to be a universal law that everyone, when he thinks himself in difficulty, should be able to promise whatever he pleases with the purpose of not keeping it, the promise itself would become impossible as well as the end one might have in view of it, since no one would consider that anything was promised to him and would ridicule all such statements as vain pretences.”

To promise with the intention of reneging the promise undermines and contradicts the act of promising. Promising per se, would a priori, as concluded by Reason, become intrinsically inoperable. Hence, promising with the intention to renege the promise undermines the very act of nature promising thereby preventing it from becoming universalised. Yet isn’t there an element of consequentialism here? For Kant writes that ‘no would consider that anything was promised to him and would ridicule all such statements as vain pretences’? No, the deciding factor is that it judged by Reason as a priori inconsistent as defined by the reflexive criteria of the Moral Law itself-with respect to its internal logic alone. Empirical consequences are irrelevant.

Whilst this is a tribute to the genius of Kant, is it feasible?

Kant works on an Enlightenment model of what is is to be a human being – namely Rational. Reason is to be employed in most areas of human activity. With the Categorical Imperative it appears that acting detachedly following the pure conclusions of Reason relegates what others may consider to be ‘human’ creating instead, what would be a logical automaton. Firstly, as consequences are deemed irrelevant, the human being is merely following the orders of Reason. Lying for instance, is outlawed even if it could save hundreds of lives. This could be objected to.

Secondly, is Kant’s emphasis, even superfetation of Reason a convincing model for human beings? His underlying premise of what it is to be human (I.e. a Rational being) allowing the conclusion of the Categorical Imperative can be challenged. Finally, Kant’s conception of the human being is atomistic and innatist. It’s essential identity both particular and universal, arises from an innateness planted within by Nature. What is within is Reason. This allows the Categorical Imperative to function. Alternatively, what a human being is, including its moral norms and practices, is collectively acquired from ‘without’, from society. We must look therefore at the broader panoramic of society and its dynamics to link certain ideas (including moral codes and practices) with definite states, stages of a society?

 

Analyzing Descartes’ ontological argument for the existence of God

Rachel asked:

Explain in detail any one of Descartes’ three arguments for god’s existence in the meditation. Is the argument valid? is it sound? Analyze and explain in detail.

Answer by Tony Fahey

Hi Rachel, as far as I know, and of course I may be wrong, there are only two arguments for God’s existence in Descartes’ Meditations. The first appears the third mediation, and the other in the fifth. However, since you are only interested in one let us look at the argument of the fifth meditation which is known as the ontological argument. This is an a priori argument for the existence of God. That is that evidence is not based on empirical evidence, but on analysis of the concept of God.

According to Descartes each of us possesses the idea of a perfect entity. Inherent in that idea is the fact that a perfect entity must exist – because, as Anselm had said, a perfect entity can only be perfect if it has existence. Neither could we conceive of a perfect entity if there was no such thing. We are imperfect, said Descartes, so the idea of perfection cannot come from us. Descartes reasons that the idea of a perfect being must have been placed in him by a really existing perfect being – God. That God exists was therefore as self-evident to Descartes as that a thinking being must exist.

Descartes believed that the idea of God was innate; it was something we are born with. The more self-evident a thing is to one’s reason, the more certain it is that it exists. From this he concluded that he was a thinking being and that there exists a perfect entity, God. With this as his departure point, Descartes lays out his theory of dualism. With regard to all the ideas we have concerning outer reality, there is possibility that we are deceived. We think we have a body but we may be dreaming; we cannot be certain that we have a body. Descartes believed his body and the non-conscious natural world was non-essential, that is, contingent. It is important to realise that Descartes is not saying that the material world does not exist, but that its existence is radically unlike that of the mind. His body is not part of his essence, therefore, if his body ceased to exist, his mind would not cease to be all that it is. In other words, Descartes would continue to be Descartes even if he had no body.

There are two kinds of reality – two substances – says Descartes. One is thought, or mind, the other is extension, or matter. The mind is purely conscious and occupies no room in space and therefore cannot be subdivided into smaller and smaller parts. Matter, on the other hand has no consciousness. Descartes maintained that both mind and matter originate from God, because only God exists independently of anything else. Although both substances come from God, they are independent of each other. Thought is independent of matter and conversely, the material processes are independent of thought.

One of the main problems with Descartes’ ontological arguments is one that was identified by the monk Guanilo when the same argument was advanced by his contemporary Anselm circa 1093. According to Gaunilo, the ontological argument would imply that anything, no matter how fictitious or chimerical, which was thought in the mind, would have to exist in reality. To prove his point he uses the example of an ‘island more blessed than any other, a perfect island… greater than which nothing greater can be conceived’. Given Anselm’s ‘proof’, he argues, if one can conceive of such an island in this way, then it follows that such an island must exist in reality as well as in the mind – this, of course, is absurd.

 

Answer by Geoffrey Klempner

There is a way of seeing the ontological argument as being valid but not sound. A being like God, being perfect in every way, cannot contingently exist. That seems reasonable. A perfect island can never be THAT perfect. We can imagine some universe where there is a perfect island and another universe where there isn’t a perfect island. But IF we can conceive of God as God, that is to say, having the attributes of perfection attributed to Him by Anselm and Descartes, then God, IF he exists in any possible world must exist in all possible worlds.

That’s a valid argument for the existence of God, from the assumption that the conception of God is not incoherent or self-contradictory. But that’s an assumption which a critic of the ontological argument would question.