Riku Sayuj's Reviews > Doubt Truth to Be a Liar

Doubt Truth to Be a Liar by Graham Priest
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Book 3: The Basic Instruments Of Philosophy

Doubt Truth to Be a Liar’, ostensibly the book being reviewed here, is a championing of the ideas of  dialetheism , which argues that some contradictions can indeed be true. Priest mounts an effective challenge against Aristotle’s fundamental Law of Non-Contradiction (as we will see, it is the heart of Book 3), and against the many philosophies and arguments that have grown up around Aristotle’s First Principle. This book is much more than a discussion on this particular book of the Metaphysics and touches on a variety of other Aristotelean works. But since I want to have something on each book of my Metaphysics reading up (so that I am forced to move to the next book only after I organize and summarize my notes of the former and because this book was a fascinating and well-argued counter to Aristotle’s flat-out assertion, and especially since the Symposium Aristotelicum is not available for this particular book) I have chosen this review as a place to primarily discuss Book 3 -- This is a disservice to Priest’s book which is wonderful reading if you want to explore further the role that contradiction plays in our thinking and logical maneuvering. Do check out other reviewers for more on the book.

To read about other Books of The Metaphysics, see here:  Book 1: A Preliminary Outline of Philosophy  & here: Book 2: An Introduction to Philosophical Problems.

I am using my parallel readings on Aristotle & Metaphysics to keep my notes/understanding of each book in separate pockets before bringing them together in a final review, if that is possible.

Book Gamma: Going Further

After the historical surveys and problems discussed in the first two books, Aristotle is now in a position to give his famous assertion on what is presumably his definitive statement of what philosophy and especially metaphysics is — It is the study of "being qua being". That is, while other sciences investigate limited aspects of being, metaphysics investigates being itself. This study of being qua being amounts to be the same thing as the study of the primary causes and principles, which has previously been said to be the task of philosophy, because the primary causes and principles are the causes and principles of being qua being.

This is because Being itself is primarily identified with the idea of substance, and also with unity, plurality (as we are later told, philosophy will interest itself in plurality, the contrary of unity, since all sciences study contraries, and so consider difference, dissimilarity, etc.), and a variety of other related concepts. Aristotle implies that he will be investigating these soon.

But before he sets out on the investigation, Aristotle needs to make his readers familiar with the basic tools of argumentation since proper, rigorous philosophy is also concerned with logic and the principles of demonstration, which are also very general, and hence concerned with being itself — In making this addition, he is resolving the dilemma posed by puzzle 2 of book Beta. Ideally, Aristotle seems to be saying, the reader should already be familiar with the Organon’s arguments before he/she goes further than this book. The bulk of the rest of book Gamma is, accordingly, devoted to the defense of the fundamental principles of demonstration/logic. Aristotle evidently feels that it will not be possible to be certain about the conclusions later to be drawn about substance, unless the principles of demonstration itself have first been vindicated.

The most fundamental principle according to Aristotle, the only thing he is prepared to elevate to the level of an axiom, is the principle of noncontradiction: nothing can both be something and not be that same something. To Aristotle, this is the First Principle of logical demonstration, which though not of course deducible, is the ultimate principle governing all being and all knowledge. Aristotle defends this principle exhaustively by arguing that it is impossible to contradict it coherently. Aristotle also presents in this connection the principle of non-contradiction is the Principle of the Excluded Middle, which states that there is no logical middle position possible between two contradictory positions. That is, a thing is either x or not-x, and there is no third possibility in-between those two positions.

Back on The Attack

Book Gamma concludes by looking back at Books 1 & 2 and uses the new principles the readers have now been made familiar with to launch another attack on, and reject, the several general claims of earlier philosophers: that everything is true, that everything is false, that everything is at rest, and that everything is in motion.

Aristotle proves that these claims amount to a rejection of the principle of non-contradiction. First, he deals with those who claim either that everything is true or that everything is false. Each of these claims is in fact self-destructive: if everything is true, then so is the denial that everything is true, and if everything is false, then so is the claim that everything is false. Secondly, he also refutes those who claim either that everything is at rest or that everything is in motion. That everything is not at rest is shown by the fact that the very proponent of the claim himself came into existence at some time in the past. That everything is not in motion is shown by the fact that for anything to be in motion there must be something which is not in motion and also by the fact that there are some things that are eternal.

The question of Motion, whether there is something permanently in motion and whether there is primary cause of motion which is itself permanently unmoving, is to be explored at greater length in book Lambda. In this book Aristotle expertly connects this fundamental exploration of metaphysics to the mistakes of his predecessors by subjecting them to the scrutiny of, according to him, the most basic techniques of demonstrative philosophy. After Book 2’s seemingly ‘unsolvable’ puzzles, if any reader felt that they might be in for a shaky and doubtful ride, this book shows that Aristotle is completely in control of the voyage and knows exactly where he is sailing. No worries.
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Reading Progress

May 15, 2014 – Started Reading
May 19, 2014 – Shelved
May 19, 2014 – Shelved as: to-read
May 19, 2014 – Shelved as: aristotle
May 19, 2014 – Shelved as: direct-phil
May 19, 2014 – Shelved as: books-about-books
May 19, 2014 – Shelved as: r-r-rs
May 19, 2014 – Finished Reading

Comments Showing 1-12 of 12 (12 new)

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message 1: by Yann (new)

Yann Very nice review! Logic looks like a good tool, but should be used with prudence.

Riku Sayuj Yann wrote: "Logic looks like a good tool"

I just fell off my chair!

Thanks :)

message 3: by Yann (new)

Yann Riku wrote: "Yann wrote: "Logic looks like a good tool"

I just fell off my chair!

Thanks :)"


message 4: by Ted (new)

Ted So at this point Riku, do you see yourself as a Platonist or an Aristotelian? (I think I know the answer --> (view spoiler), but of course I could be wrong.

What would Aristotle say to the assertion that something can be both "good" and "not good"; which assertion seems self-evidently true? I suppose he would say (quite reasonably) that this is only true if the "good" and "not-good" are asserted about different aspects of the thing. But I'm not sure he can escape quite that easily, if could get very complicated.

Fuzzy Logic is another conundrum as Elham says.

Anyway, I have immense admiration for your project of delving into these ancient philosophers. It is definitely a young person's quest.

Riku Sayuj Ted wrote: "So at this point Riku, do you see yourself as a Platonist or an Aristotelian? (I think I know the answer --> [spoilers removed], but of course I could be wrong.

What would Aristotle say to the ass..."

I am huge fan of both at this point, but leaning towards Plato -- primarily due to presentation and not due to the content / any doctrinaire reasons. What I have learned is that the Platonist/Aristotelean dichotomy is created only if you take Platonism as what Aristotle reduces it to be. As long as you treat both on their own merit and first-hand, there is not much real conflict between the positions. At best we can argue about which is a more advanced position.

About good / not-good, Aristotle (and Plato) would ask us to define 'goodness' first and by the time we have worked out what the real 'good' means in any situation, the conflict might well have resolved itself. Usually we want to have a superficial understanding and categorization and run after a quick good / not-good judgement... lot of modern political debate, for eg.

Fuzzy logic is more a tool than an actual form of reasoning... it has to be employed when what we are dealing with is too complex to be reduced to contraries... of course, I need to read more on it to see if that can be brought into an Aristotelean framework.

Thank you so much, Ted. It has been a wonderful ride so far. There is much excitement in these works.

message 6: by Riku (last edited May 19, 2014 09:49AM) (new) - rated it 4 stars

Riku Sayuj Elham wrote: "Another great and thought provoking review, thanks Riku! (BTW, have you ever read anything about Fuzzy Logic? It's related to mathematics and considers values between x and non-x!)"

Thank you so much, Elham - for the kind words as well as for throwing fuzziness into the mix! I will read more and come back to this.

Riku Sayuj Elham wrote: "I think he is a Platonist (Just check his favorite authors, the first one is Plato, and no Aristotle in the list!)"

Hey! I don't add an author until I am well acquainted, is all. A is definitely going there. :)

Riku Sayuj Elham wrote: "Fuzzy Logic is for conceptions that we can not categorize them in a 0 or 1 system. For example the adjectives like fat, tall, beautiful... Who is fat? If we say anybody whose weight is more than 80 kg is fat, then according to this system one who weighs 79 kg is not fat, nor is the one who is 79.9 kg or 79.99 kg or 79.999999 kg... . Everybody who weighs less than 80 kg is not fat(0) and anyone who weighs more than 80 kg is fat(1). So this kind of logic (0 or 1) is not acceptable in real life. Fuzzy Logic suggests a system which deals with values between 0 and 1. In this way for example one whose weight is 79.9 kg has a ratio of fatness! "

Fuzzy logic for fuzzy concepts, in short? As i said about goodness above, A will only say that the concept being examined is not well defined and that is why we cannot have a proper x/not-x when examining it. Of course, we might be able to convince him that in some concepts, human capability to understand the concept is limited and it might be best to incorporate that fuzziness into the tool of examination than insisting on concrete told and ruin the results completely. I have to check what he has written about Meteorology, for instance.

Riku Sayuj Elham wrote: "Riku wrote: "Fuzzy logic for fuzzy concepts, in short?"

It's more related to mathematics than philosophy, I think. I have a book Fuzzy Reliability in Industrial Systems which is full of formulas a..."

True, but mathematics was squarely within the purview of philosophy back then.

message 10: by Ted (new)

Ted Riku wrote: "Elham wrote: "Riku wrote: "Fuzzy logic for fuzzy concepts, in short?"

It's more related to mathematics than philosophy, I think. I have a book Fuzzy Reliability in Industrial Systems which is full..."

Perhaps "within the purvey", particularly if we think (in contemporary terms) of the >i>philosophy of mathematics, much of which is descended from Plato. But Euclid isn't thought of as a philosopher; neither is Archimedes. Real mathematics has that "engineering" bent to it that philosophy lacks.

message 11: by Riku (new) - rated it 4 stars

Riku Sayuj Ted wrote: "Riku wrote: "Elham wrote: "Riku wrote: "Fuzzy logic for fuzzy concepts, in short?"

It's more related to mathematics than philosophy, I think. I have a book Fuzzy Reliability in Industrial Systems ..."

I am not sure I understand why 'purvey'...

but about the engineering bent, that is precisely what Plato and Aristotle wanted to bring into Philosophy. And only because they were able to, later mathematics could mature and venture out on its own. The whole concept of 'arete' (commonly mistranslated as 'virtue' - but should be called 'excellence') has a distinctly engineering/workmanship based feel to it.

(Pythagoras was surely more far out than any philosopher, btw.)

message 12: by Ted (new)

Ted Riku wrote: "Ted wrote: "Riku wrote: "Elham wrote: "Riku wrote: "Fuzzy logic for fuzzy concepts, in short?"

It's more related to mathematics than philosophy, I think. I have a book Fuzzy Reliability in Industr..."

I meant purview, your word.

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