Probing DD’s Standard: Truth Is Consistent With Itself

Posted in Blogosphere, Epistemology, Philosophy on  | 4 minutes | 9 Comments →

I recently stopped by DD’s blog to see what sort of arguments are on offer, as I usually do every few months or so. Today, I’d like to raise some questions relating to DD’s standard of evidence as delineated in his post, Alan Roebuck and the Covert Materialism. DD writes:

…if there is some evidence that is better than the rest, believers could and would bring that evidence to the forefront. This fact invalidates the Courtier’s Reply because if there were good evidence, then the dialog between believers and unbelievers ought to focus on that. If good evidence does exist, then there’s no point in complaining that skeptics have failed to study the bad stuff. Bring out the good stuff, and let’s see how they deal with that. And conversely, if it’s all equally bad, then an exhaustive study of all the bad evidence would be merely a waste of time.

First off, we seem to have differing opinions about why people use the so-called Courtier’s Reply. I’ve never been of the opinion that the Courtier’s Reply is for skeptics who haven’t studied the bad stuff. Rather, any so-called Courtier’s Reply I’ve given is usually towards skeptics who’ve failed to study the good stuff.

In my experience, many skeptics simply gloss right over, say, Aristotle’s argument from kinesis, with nothing more than a pedestrian one-off like, “Well, who made God?” That is when I claim the skeptic needs to make a more concerted effort to learn about that which they pass judgment on, but enough of that. The part I really want to digest is here:

As for insisting on a standard that makes proving God impossible, I’ve insisted on only the most reasonable of standards: that truth is consistent with itself. That’s the same standard I use for everything, and it’s not a hard standard for true things to meet because it is the nature of truth to be consistent with itself. […] The bedrock foundation of truth is that truth is consistent with itself; any contrary definition of truth must necessarily be a self-contradiction, and therefore false. Truth exists as an objective reality outside of and independently of the worldview (lens) with which we view it.

I agree that what is true remains true regardless of the worldviews we hold, and I also accept DD’s basic point here: truth is consistent with itself. If it is true that Mr. Johnson was in Atlanta on December 3rd, 2011, we would expect to find other facts consistent with this truth, perhaps some travel records, or photographs of Mr. Johnson at a Braves homegame. However, despite the internal consistency, do these things prove that Mr. Johnson was really in Atlanta on the day in question? Of course not.

When DD says “truth is consistent with itself,” he’s offering a statement that reduces to tautology. He is, in essence, simply saying, “Truth is consistent with truth.” Okay, sounds great, but how do we know what’s true to begin with? Surely, it follows that falsehood is consistent with falsehood, and we all know that falsehood often masquerades as truth.

It was once thought to be true that the sun revolved around the Earth. If we are mistaken about what we believe to be true to begin with, DD’s principle can lead us to all sorts of error. “Truth is consistent with itself,” the geocentrist could proclaim. “One can plainly see that the sun makes a journey around the Earth.” Or, take cathode rays. “Truth is consistent with itself,” Plücker could have proclaimed. “One can plainly see that objects placed between the cathode and an interior wall cast shadows. Therefore, whatever is being emitted by the cathode travels in straight lines.”

Both of these conclusions are consistent with their starting premises, yet, so far as we know, both conclusions are also false. So, since valid arguments can clearly be unsound, what is the value of a standard that essentially checks for validity, as opposed to soundness?


  1. erbdex


    Good post.

    Plato’s ‘The Republik’ gives a great insight on the matters of ethics, code of conduct and the clichéd ‘Truth’.

  2. cl


    Thanks. What do you think of DD’s standard? What do you see as its strengths and/or weaknesses?

  3. Nice to see you back, CL.

    I think consistency is certainly a necessary condition of truth but is not sufficient. From glancing at DDs blog, it doesn’t seem like he necessarily meant that it was a sufficient condition either.

  4. cl


    Yeah, I’m not sure. At times, he certainly acts like it’s a sufficient condition. For example, DD argues that God “not showing up” is consistent with God as myth. He then arrives at the conclusion that God is probably a myth based on nothing more than this superficial consistency.

    So, I don’t really know what his standard is.

  5. Rufus


    “To have logical clarity and consistency is admirable. But to have only logical clarity and consistency is pitiful. In fact, it is a mark of insanity…” (P. Kreeft 2005, Socratic Logic, p. 9).

  6. I am sure you have read this in the past but I would like to hear your reply given that this seems to me a double edged sword which would cut into any arguments, scientific or religious. As I am new to this blog I would be happy to read ant redirects you might have to previous responses.

  7. cl



    Huh. You managed to find something that articulates exactly what I was thinking!

    Christopher Vena,

    Howdy. Thanks for stopping by. Actually, I hadn’t read that. I gave it a brief perusal, but I’m too busy to justify reading what looks like a rather thoughtful paper at the moment. But I will check it as time allows. Although, I do have a question: when you said, “this seems to me a double edged sword which would cut into any arguments, scientific or religious,” what exactly did your “this” allude to? The eventual conclusion of the paper in question? Something I said? Something else? Perhaps you can clarify exactly which part of the paper you see as relevant to my post…

  8. Rufus



    Kreeft wrote that with reference to Chesterton’s Manic passage from Orthodoxy.

  9. Rufus


    I’m sorry maniac, not manic. :-D

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