The Copy Principle is David Hume's version of the old empiricist slogan, "Nothing in the mind that is not first in the senses" (Locke's "Tabula Rasa"). [Aside: it is more accurate to treat this as an anti-nativist slogan, but many empiricists have in fact accepted some claim along these lines, so we'll ignore the inaccuracy for the time being.]
Specifically, Hume thought that every idea we have (indeed, every idea we could have) is either (a) a copy of some impression or (b) constructed wholly from ideas that are copies of some impression.
Two notes: First, remember that we're talking about Hume here, so in this context the term "idea" refers to a subset of, for instance, Locke's Ideas. Here, "idea" means, roughly, concept or thought.
Second, I assume that Hume did not think that the Copy Principle just happened to be true of all of our ideas--I take it that he thought it was true of any idea we could, in principle, have as well.
Hume used the Copy Principle to discover the limits of what the human mind could meaningfully think. For if one cannot, at least in principle, trace an idea back to the impressions from which it was copied, then it was not a meaningful idea at all. At best, it is just a copy of some sound we have heard. Since meaningful thoughts can be built only from meaningful concepts, all meaningful thoughts are wholly composed of ideas that can be, in principle, traced back to impressions.
Using the Copy Principle, Hume argued that traditional metaphysics (of the sort offered by, for instance, Rene Descartes) was littered with meaningless concepts, concepts such as Cause, Substance, and Self, which could be traced to no impression. Philosophy, insofar as it deals in meaningful thought at all, must be confined to experience (or what can be "constructed" from things we have experienced).
The Copy Principle is a substantive and important thesis. What do you think of it? Is it plausible? Can you think of counterexamples? Where does Hume get the principle? What reasons does he offer for it? (Think of "Hume's Fork" here, and think about on which prong the Copy Principle might be found.) And how are we to assess Hume's use of the Copy Principle against apparent counterexamples? Is there any non-question begging way to use it?
It is interesting to consider evaluating the Copy Principle by means of the self-applicability test. Indeed, it seems difficult to conceive of the Copy Principle applying to itself. Could we, however, assert that perhaps the impression of all the thoughts Hume has directly or indirectly experienced have led to the Copy Principle as a copy of this overall impression? I would imagine that many epistemological theories share this difficulty of applying to themselves, as any claim pertaining to all thought or knowledge should also, in principle, apply to itself. Perhaps, though, a thought that constitutes a generalized attempt at qualifying all thoughts should be considered a special kind of thought? But this thought would necessarily belong to the category of "all thoughts", which brings me to the observation that any theory regarding "all" thoughts is especially vulnerable to self-contradiction. Just some thoughts :) (sorry!).
ReplyDeleteI also had a question regarding the verifiability principle; that a statement is only meaningful if it can be supported or refuted - verified - by real-world observations. In class, Dr. Wallhagen mentioned that it is often argued that the verifiability principle itself is not verifiable. However, it seems to me that the verifiability principle is essentially a definition of the concept of a meaningful statement, and that all definitions are fundamentally arbitrary. It seems rather unreasonable to expect that a definition can be verified by empirical data; just like the definition of the word "cow" as referring to the particular animal is wholly arbitrary and thus cannot be supported or refuted, definitions generally do not seem subject to verification. Would we then say that all definitions are "meaningless" in that they are not verifiable?
Great comment, Theo. I hope others read and react! I'm biting my tongue for the time being (ouch). :)
ReplyDeleteHm, I'd still like to see another student react to Theo's suggestion about how to defend the Verifiability Theory of Meaning. In the meantime, I'll comment on a couple of things.
ReplyDeleteThere are some epistemological theories that pretty clearly do avoid self-applicability problems. Consider Rationalism: some substantive knowledge can be justified through thought alone. Notice that the Rationalist thesis need not itself be an instance of such knowledge!
Moreover, not every fully general epistemological theory suffers from self-undermining problems. Consider Empiricism: all knowledge is ultimately justified by appeal to experience. It isn't obvious that this claim should not itself be ultimately justified by experience. (And I think one can say this without begging the question.) Moreover, it is open to the empiricist to claim either that knowledge of Empiricism itself is not "substantive knowledge" or that we do not really have knowledge of the truth of Empiricism (granted, I find both of those options pretty unsatisfactory, but they don't seem to be problematic from a purely logical point of view).
I think the points I've just made suggest that you don't have to regard general claims about knowledge as special types of thought, but that is not an unheard of move. In fact, many philosophers distinguish "first order" thoughts and claims from "higher order" ones. On this view, the Copy Principle is really something like: Every first order idea is a copy of some impression (etc.). Ok, but why should higher order ideas be exempt in this way? Could Hume really treat them as exempt, and still be an empiricist? If a higher order idea need not be a copy, why persist in supposing that first order ideas must be? This is a common problem with the "special type of thought" response to the objection that a certain claim is self-refuting or self-undermining.
I'm tempted to comment on the claim that definitions are fundamentally arbitrary, but I'll hold off on that for now...
I certainly agree that considering general claims about knowledge as special types of knowledge is unnecessary and probably would compromise the strength of the claim. Regarding Empiricism, as I discuss in my research project, I would also agree with your point that the principle of Empiricism does not necessarily contradict itself in that it may ultimately be considered as derived from experience, itself - the thought "all knowledge is ultimately justified by appeal to experience" may very well be regarded as having its roots in experience. Indeed, this thought would be difficult to conceive of as originating completely independently from any experience whatsoever. Finally, I am also interested in the notion that the principle of Empiricism should not be considered as an instance of knowledge, but rather as simply a suggestion or guideline for evaluating knowledge.
ReplyDeleteQuick comment on the final sentence of Theo's latest reply: the suggestion that Empiricism be treated, not as something known, but as a suggestion, or guideline is clever. I'm not convinced it works, though, and here's why. I find it difficult to believe that the empiricist doctrine is not a candidate for belief. But if so, isn't is something for which we can seek justification? It seems to me that it is. Moreover, it seems that we can understand having better or worse justification for it. In sum, it doesn't seem implausible to treat it as a candidate for knowledge. And if that is true, the empiricist is obligated to explain how we can have empirical evidence for it.
ReplyDelete