Friday, February 12, 2010

There is Truth

In the comments to the last post, commenter "onus probandi" accuses me of a petitio principii by taking for granted that there is truth to be found in philosophy. But begging the question is when one assumes what one ought to or is trying to prove. I was not trying to prove that there is truth. First principles cannot be proven. If they could be proven, they would not be first. First principles are those truths whereby other truths are recognized. They are also supposed to be self-evident, that is, apparent to anyone who understands them. So, when onus says:

we have yet to determine that there is such a thing as 'truth'

I answer: what would a demonstration that there is truth look like? How would you recognize it? What principle could you start with without already assuming that there is such a thing as truth and that it is what is reached in demonstration? The very notion of demonstration presupposes the notion of truth.

"Something is true" is a first principle. However, like other first principles, it can be evinced - not demonstrated - by showing the absurdity of rejecting it. Consider the following proposition:

"There is no truth."

If the proposition is true, then there is truth. If the proposition is false, then there is truth. Even the act of denying that there is truth proclaims that truth exists. "There is no truth" is literally un-believable.

Other statements that are not only false, but self-evidently so:

"Nothing exists." Your claim and the sentence embodying it exist!

"Everything is illusory." Your suspicion that everything is illusory is not illusory, and neither is your mind which considers it: for an illusion is only an illusion for someone conscious of it.

"The world is meaningless." At least something in the world is meaningful, namely your opinion, which is false but not without a sense.


onus probandi said...

"In the comments to the last post, commenter "onus probandi" accuses me of a petitio principii by taking for granted that there is truth to be found in philosophy. But begging the question is when one assumes what one ought to or is trying to prove."

Well, firstly, I fear you may have put things all too severely (but I suspect that perhaps it is more so the case of it being a consequence of that albeit inadequate distillation of thought in the subject remarks as only my poor mind can furnish) that you mistook my comments as my hurling any such accusation against you personally; rather, it was more so in connection with the citation provided earlier in your preceding post.

To me, it seemed an example of petitio principii because within the very context of the cited passage, it appeared to me to assume the 'Truth' of a Christian God.

However, for my or anybody, for that matter, to concede to such an assumption at the onset without the person (the one submitting such an argument) initially putting forth a case (strong or otherwise) for such a 'truth' without actually proving it to begin with, seems to me a grand example of petitio principii.

This is the stuff that all such fallacies consist, as I'm sure you'll agree.

Yet, I must thank you though that your recent posts (particularly those which you've presented in the passing week) have been particularly thought-provoking as they have been amusing.

I look forward to many more such posts.

Brandon said...

Petitio principii doesn't arise merely for a lack of a supporting argument: otherwise everyone would continually be committing it because it is simply not feasible, and often not reasonable, to argue for everything one says, or, indeed, everything one asks one's fellow discussants to concede. You can only have a petitio principii where (1) the conclusion is provably the same as one of the premises or ineliminable assumptions of an argument; or (2) the conclusion of the argument is provably more fundamental than the premises from which it is allegedly derived, when the premises are put forward as reasons why the conclusion is true rather than as merely signs that it is.

onus probandi said...

Mr. Brandon,

The petitio principii I am referring to in the subject passage is the one that assumes (at least, by how I've read it; which, admittedly, may be subject to correction) by implication the truth of the Christian God.

It seems the same sort of petitio principii evident in a politician's speech concerning some such thing as 'wasteful spending' and what not, which would have the unwitting hearer of such speeches to concede at the forefront what the politician considers 'wasteful spending' without his (i.e., the politician himself or rather, more precisely put, more likely a demagogue) having not first made an argument that any such spending is actually wasteful.

The immediate (or, perhaps better, the underlying) context of the passage strikes me as doing something similar in that it seems to me to have already assumed that the Truth of Christianity is itself true without any such corroboration (in this case, an actual argument put forth by the person) that it is.

While I continue to hold much respect and appreciation to all you gentlemen for your wisdom and thought (not to mention, charitable patience) in the matter, I would have to differ -- at least in regards to this.

Brandon said...

Again, assumption has nothing to do with petitio principii: you only commit petitio principii when you present an argument whose premises cannot be accepted without a prior acceptance of the conclusion. A politician who talks about 'wasteful spending' without argument in such a way as to slyly get others to concede without adequate reason that the spending is in fact wasteful might be engaging in rhetorical trickery, but he is not committing petitio principii.

Think of it this way: Petitio principii by its nature is a fallacy of argument: it's an argument in a circle, an argument that is question-begging. If you have not made an argument, you cannot possibly have committed a fallacy of argument. Therefore if you have not made an argument you cannot possibly have committed petitio principii. But if you have assumed or proposed something without argument, by supposition you have not made an argument. Therefore you have not committed petitio principii.

It is possible, of course, for someone to assume something that in fact needs to be proven, in the context in which he assumed it; but this is a purely pragmatic matter not an argumentative one, and would need to be proven on a case-by-case basis because it will depend on circumstances, and is not a fallacy, because fallacies are a species of error in argument.

Michael said...


I fear . . . that you mistook my comments as my hurling any such accusation against you personally

Not at all!

within the very context of the cited passage, it appeared to me to assume the 'Truth' of a Christian God.

The immediate (or, perhaps better, the underlying) context of the passage strikes me as doing something similar in that it seems to me to have already assumed that the Truth of Christianity is itself true without any such corroboration (in this case, an actual argument put forth by the person) that it is.

I believe this is incorrect. The context of the passage is from Aquinas' Commentary on the Metaphysics, which is not a theological work and contains practically nothing about Christianity. Indeed, the only time Christian doctrine is mentioned in Aquinas' Aristotle commentaries is in passing, on those rare occasions when Aristotle's doctrine is really contrary to the Catholic faith, and then only to mention that Aristotle's opinions which are inconsistent with Christianity are speculative or probable, rather than demonstrative. So the context of the quoted passage is that of philosophical truth, not theological truth per se. Aquinas is pointing out that it's useful to read people like Plato and Aristotle, both for what they got right, so that we can learn from them, and for what they got wrong, so that we can avoid their mistakes.

I look forward to many more such posts.

Thank you for your kind words. I'll do my best.

onus probandi said...


Thank-you for that clarification. I had mistakenly formed the conclusion (rather hastily, it seems and without warrant) that it concerned matters of Christian theology, as the mere mention of Aquinas typically does in various discussions that usually involve him (at least, in those subjects that have commonly involved citations of his works).

I shall have to rectify the situation by engaging in a more in-depth investigation (at least, as far as personal time allows) of this particular work of his.

Your brief comments concerning it helps provide a summary introduction, which I, again, am grateful to you in that regard.

By the way, you had mentioned you were an actual participant in a Great Books program; would you happen to be interested in commenting on it and your experience having personally taken advantage of such a curriculum?

First Principles seemed to have laid some sharp criticism concerning it at their website, regarding which I would be very much interested in your own opinion about it:

The Great Books Curriculum

"Though admitting shortcomings, Bloom recommended a Great Books curriculum (effectively meaning the Great Books of the Western tradition) as the best solution to the vacuity of contemporary higher education. The Great Books, he thought, would expose students to the best that has been thought and said in the world. By introducing students to the finest minds in Western history, and letting them have unmediated, open-ended dialogue with them, the Great Books would sharpen students’ intellects for their own ongoing philosophic quest.

Bloom’s book was a success because it exuded a love for the philosophic life and touched raw nerves in academia and in America more generally. Not surprisingly, Bloom was condemned as a reactionary crank by establishment liberals in universities and the media. But more traditional conservatives were also critical. They applauded his diagnosis of contemporary ills, but expressed strong reservations about his prescriptions. Students could not just pick up the Great Books and understand them without knowledge of the historical and intellectual context in which they were written. Many doubted that a Great Books approach would teach students anything beyond how to read and interpret texts. Simply reading and interpreting texts would not teach philosophic habits of mind. It would produce students who were oversophisticated, seeking sophistication for its own sake, but not believing that there was any real truth to grasp beyond the play of interpretations. These solitary philosophers would lack Newman’s gentlemanly wisdom and the true love that gives rise to philosophy. Finally, conservatives rejected Bloom’s claim that the United States, and the modern university, were fundamentally products of the Enlightenment and dedicated to perpetuating it. Instead of being a safe place for philosophers to exercise unconstrained reason, they pointed out that the university was a product of medieval Christendom, rightly concerned with training philosophic reason to function within a tradition of faith."

onus probandi said...

Mr. Brandon:

Petitio Principii is when the person asks the other party to concede to the main point of the argument at the onset.

In the immediate example I provided, the politician who rants about 'wasteful spending' is committing such a fallacy due to his already asking the opposing party (and the audience) at the outset to concede to the main point of his argument that what he personally considers 'wasteful spending' actually is.

The 'question being begged', therefore, is what is actually 'wasteful spending' as opposed to 'necessary spending'.

Thus, I hope you can see that this is indeed a genuine example of petitio principii.

Brandon said...

Petitio Principii is when the person asks the other party to concede to the main point of the argument at the onset.

No, this is incorrect. The phrase, 'petitio principii' describes the fallacy recognized by Aristotle in Prior Analytics II.xvi: "Begging the question is proving what is not self-evident by means of itself either because predicates which are identical belong to the same subject, or because the same predicate belongs to subjects which are identical." As Whately puts it, it occurs in "those cases in which one of the premises either is manifestly the same in sense with the conclusion, or is actually proved from it, or is such as the persons you are addressing are not likely to know, or to admit, except as an inference from the conclusion". Asking to concede something is just asking to concede something; it's not even the right category of thing to be a fallacy.

Anonymous said...

As even notes from a Stanford-educated professor accordingly confirmed:

Petitio Principii means 'begging the question'.

'Begging the question' means that you're setting things up where you're asking the other side to concede the main point --

That's what 'begging the question' is all about: you're asking the other person to concede the whole argument.

He also validated the example as being such a case of petitio principii since the question being begged in the example provided is "What is 'wasteful' spending?" versus "what is 'important' spending?", etc.

That you are unable to see that, Professor Brandon, leaves me to become skeptical of your expertise in the matter (although, you continue to hold my deepest respect not only because of your wisdom in matters concerning philosophy and religion but also for your charitable patience in that, at the very least, you were trying to teach me certain things in this regard, which I am obviously not so expert as I require such consult).

Again, you and The Smithy group here provide much for considerable rumination.

Brandon said...

Onus Probandi,

I have already pointed out to you the history of the term: I have noted that it derives from Aristotle, I have pointed out what Whately says about it; all discussions of it derive from those two sources, directly or indirectly. For your one set of defective notes from a single source I could give you thousands of notes, easily available, from a wide variety of sources (e.g., here) and articles (e.g., Woods and Walton) which actually get it right. This isn't difficult; petitio principii is begging the question; begging the question is arguing in a circle; you can't argue in a circle unless you argue; therefore failing to give an argument is not begging the question but something else.

onus probandi said...

Professor Brandon:

Actually, it's not so much 'defective notes' but a verbatim transcript of the man's lecture on the subject.

I can provide you with his credentials if need be and an excerpt of the very lecture itself for inspection if you would kindly provide me with your email address.

Now, I'm rather curious as to whose credibility is in question here.

Thanks again for your gentle patience in the matter and for your continued tutelage.

Brandon said...

I have no interest whatsoever in the man's credentials. The question at hand is simply what the standard meaning of 'petitio principii' is; I've noted the historical sources of discussions of the fallacies, the fact that there are plenty of other sources who do not characterize the fallacy this way, and pointed you to an article by Walton, who is one of the world's best-known writers on fallacies. I could add any number of other sources: De Morgan in Formal Logic, other articles on the subject by Walton, and articles by other people. There is so simply no question or doubt on the matter. It's also simply not an issue to which credibility has any relevance one way or another; perhaps your source had reasons for using the term in a nonstandard way, because sometimes such occasions arise, or perhaps he simply expressed badly what he wanted to say on that one point, but it was nonstandard, and a defective account if taken as a general account of what petitio principii typically means in this context.

onus probandi said...

Professor Brandon,

I'm so much after calling into question anybody's credentials, actually; but more so interested in whether what the man said in his lecture was actually correct and the example proffered valid.

This is why I wanted (that is, if you would be so kind enough to evaluate) to submit to you a section of the recorded lecture itself for proper determination of whether his lecture (specifically, his definition and the example cited) were indeed correct. Perhaps there may have been some nuance missing in the excerpt provided (although, I can hardly see how there could be since I've practically rendered his words verbatim).

What I am interested first and foremost is the correctness of his contentions and if whether or not his definition and example as applied to 'real life' actually stands.

It has really nothing to do with anybody's credibility but the fact that it would be a great disservice if I and others who attended his lecture were to believe that what we thought infallibly correct was actually erroneous in nature.

I am hoping you can be generous enough to evaluate this portion of his lecture immediately dealing with the topic -- not to provoke some professorial war -- but for what I believe is necessary to correct what apparently is errata.

If you prefer, I'll not even divulge the identity of the professor.