our whole problem today is the fact we believe what is not true, and the truth matters over all things, it really is bliss and will set you free

Ken has introduced the concept of a serviceable falsehood. He offers the dictum, "When it would be more useful or serviceable for the purposes of ordinary life to believe the comforting falsehood, do so."
Notice that Ken says, "serviceable for the purposes of ordinary life." Serviceability always exists in relation to some end, goal or purpose, in relation to which something may or may not be serviceable. There is no serviceability tout court, in all possible circumstances, independent of ends or purposes.
Ought ordinary life to be the criterion of serviceability? Are not there ends that are extraordinary, in relation to which beliefs could be quite serviceable, even though they may not be serviceable "for the purposes of ordinary life"?
Many spiritual paths evaluate the serviceability of beliefs not by appealing to ordinary life, but by appealing to ends, purposes and goals that fall outside the domain of ordinary life. When a Hindu or Buddhist believes in rebirth, for example, she believes that our existence stretches far beyond our ordinary life, to encompass countless prior births, and potentially limitless future births.
The same goes for political activism. In the 1970s movie Soylent Green, Charlton Heston's character discovers the truth that the food soylent green is really made out of humans, not the vegetable matter which the government claimed. This belief was in many ways disastrous for the purposes of ordinary life, as Heston's character's demise at the end of the movie attests. But this belief was also important, and for Heston's character it was worth risking all to find out if it was true.
When we turn our attention to science, we find practices which aim at acquiring true beliefs, even though these beliefs might be contrary to or subversive of "the purposes of ordinary life." For example, knowledge that the Earth is round might be indifferent or contrary to the purposes of ordinary life, but for a geologist or astronomer it is still useful to believe such things, and a good astronomer or geologist will believe it.
To me, this discussion cannot take place without talking about autonomy. There is a connection between autonomy and false belief. When we act on the basis of false belief, we give up our autonomy. If we value autonomy unconditionally, then we will want to have true beliefs even though they may be unserviceable in certain circumstances or respects. If we do not value autonomy unconditionally, then we will accept false beliefs if they are serviceable for this or that particular end.
So the question becomes, how do we value autonomy? Are we indifferent to it? Do we allow exceptions to it? Are there circumstances in which we prefer less autonomy?

Are approximations false?
Ken suggests that truth is not an all-or-nothing affair. Approximately true beliefs are, strictly speaking, false. And yet many approximately true beliefs turn out to be quite useful. Many geometry problems come to a useful resolution by assuming that pi = 3.14, even though, strictly speaking, this is false.
Ken describes this kind of belief as a "serviceable falsehood" that exhibits "truth by approximation," and I think his point can be summed up by saying that truth comes in degrees. It's more true to say that pi = 3.14 than to say that it equals 3.15, even though both claims are, strictly speaking, false. On this view, there aren't just two truth values, true and false, but more than two, with the addition of various degrees of "approximately true."
I hate to say it, but I find this view of things unconvincing. Let me explain why. To me, the simplest theory of truth that is powerful enough to account for our truth-talk holds that every proposition is either true or false, and that no proposition is both true and false. There is no third possibility, partially true or partially false, or what have you. So, is the sentence 'pi = 3.14' true or false? Well, that depends....
It depends on how the sentence 'pi = 3.14' is being used. If it is being used to express approximation, then the sentence is true. If it is not being used to express approximation, then 'pi = 3.14' is false. These are the only possibilities so far as truth is concerned.
There is no "false but aproximately true" option. Instead, what we require is an account of meaning that is sufficiently complex to distinguish between the strict meaning of a sentence, on one hand, and the approximate meaning of a sentence, on the other hand. 'pi = 3.14' is true when the sentence has approximate meaning; false when it does not have approximate meaning.
If what I'm saying is correct, then approximation has to do with meaning, not truth. A belief may approximate the truth without being false, if the content of the belief is itself approximate. A sentence may be approximately true without being false, if its meaning is approximate.
In short, when we say that 'pi = 3.14' is approximately true, we're not saying that there is a third truth value, approximately true. Rather, we're saying that the meaning of 'pi = 3.14' is such that, when it is approximate, it is true. Otherwise, we multiply truth values unnecessarily.

I agree that "serviceable falsehoods " are really truths.
I agree that approximations are truths.
I disagree however that every proposition is either true or false. That view, at least if unqualified, leads to confusion and problems.
How so?
Here's how I like to sort matters out. At least to a point.
Truth is ultimately a utilitarian concept. Utility is defined by desires. Whether a given proposition is true or not depends on the attending desires.
Desires are variable from person to person and also, with respect to a particular individual, from time to time.
Thus in the collective sense (among multiple persons) a given proposition can be true and false at the same time; and true on one occasion but false on another.
As just one example, no measurement of the length of any physical object can ever be known to be or not be the "true" length of the object being measured because of the inherent imprecision of such affairs and/or as a consequence of the mind/matter dichotomy.
A proposition can be "either only true or only false" only in the context of a single person and at a single time.
Truth is ultimately subjective.
Truth exists only in a context -- the context of the consciousness of the individual and his/her desires -- (and that, in the context of the material world) -- and cannot be known to exist absolutely.
Because of solipsism (one's desires not ultimately being known by another) also, truth is subjective and nonuniversal.
Does truth matter? Yes because desires matter " by definition".
(What about logical truths? Is it not absolute truth that x = x ? But there may be persons or beings who can comprehend otherwise so I would say even these are subjective. The only way human beings can understand things is in terms of their desires so for human beings everything is subjective. Even if god handed me an absolute truth I could not know it as such because the only terms in which I can comprehend it is through my desires. Well then if I am convinced that I see that something is absolute truth is it then absolute truth? I suppose so for me who sees that but not for others who don't. And then we're right back to our same old philosophic problems.)
What is desire? It is a manifestation of consciousness. But consciousness itself is unexplained.
Explaining consciousness would seem to offer the hope of resolving the problem of solipsism, the mind/matter dichotomy and would allow for universal and absolute truth.

Truth: serviceability or correspondence?
The claim that truth be defined as serviceability in relation to individual desire, in my opinion fails to handle -- indeed cannot handle -- the concept of truth.
Take, for example, persons A and B who disagree about whether Jones is good. A says Jones is good; B says Jones isn't good. Now, if Jones is serving the interests of A's desire, but not serving the interests of B's desire, then there is no disagreement. A and B are both right; their claims are both "true." Thus we are presented with an aporia: A and B make contrary claims (both can not be true), and yet their claims do not disagree (both can be true).
Indeed, one wonders how there could be any genuine disagreement at all. I say it tastes great; you say no, it's less filling. So long as each truth serves our respective desires, we would not really be disagreeing. That seems absurd. We live in a world in which disagreement over good and bad, right and wrong, are important features of life, features that it would be foolish to drop simply because we've decided at long last to define truth as serviceability for subjective desire. I believe it's wrong to invade Iraq; the president believes it's right. Great! No disagreement here. Winston in the book 1984 believes that 2 + 2 = 4; his torturer claims it equals five. Awesome! No disagreement here.
Consider what happens to our concept of meaning if truth gets defined as serviceability for individual desire, not correspondence with reality. Usually we take language, beliefs, maps,. etc., to be about something. This about-ness, meaning or intentionality, possessed by beliefs and the like, is one of the facts being explained by a correspondence theory of truth. It's because the content of a belief somehow fits the world that we say it is true. We call this fit correspondence. Not because we're trying to denounce personal preference, but because we're trying to account for the fact of meaning.
And, consider what happens to our concept of cause. Typically we think that reality causes a true belief to be true. If the sentence 'The cat is on the mat.' is true, it's because the cat really is on the mat. But if we try to define truth as serviceability for desire, not correspondence with reality, then this causal feature of truth gets lost. It's my desires alone which cause a belief to be true, not the way the world is. Once this causal connection with reality has been severed, any attempt at connecting our knowledge up again with reality becomes problematic at best. When is a claim true? When it conforms with our desire. How do we know whether it conforms with our desire? We can't. We're stuck in an endless regress of conformity with desire. We can't even know what does and doesn't conform with our desire because we can't ever get to the bottom of things. If we balk at this and say that in the case of knowledge truth is different, then we have multiplied the meaning of the word 'truth' into a general sense (function of desire) and a special sense (knowledge-truth, not a function of desire). At this point things start smelling very fishy.
Finally, regarding assumptions, I actually agree that here serviceability does play a significant role. For example, the most important work in mathematics in the 20th century involved the assumption that the equation '0 = 1' is false. This amounts to assuming that mathematics is consistent. We can't prove that math is consistent. But we can assume it. And, it turns out to be quite a useful assumption. Even so, if an assumption really is true, it's true not because it conforms with our desires, but because it corresponds with reality. So even in the case of assumptions, correspondence is still the arbiter of truth.
In conclusion, a correspondence theory of truth matches our beliefs about how knowledge and meaning work, and about how reality causes true beliefs to be true. Serviceability does not. If serviceability does play a role for truth, it's in helping us decide which assumptions to make. When we must decide whether a claim is true, we may consider serviceability; but as to whether the claim itself really is true or not, correspondence is the final arbiter.

One area in which serviceable falsehoods reign is in the area of politics. For instance, we are lead to believe that the death penalty make us safer because it is a deterent. Of course, that is false. But it is widely believed and used as a argument in favor of the death penalty.
We tell people their vote counts, to bolster the idea of our democracy. Yet, a single vote by an average citizen has little effect. Think electorial collge.....
This idea of the servicable falsehoods may be offensive to some, but it is quite true in many areas. Politics is just one where there happens to be allot of examples.

Correspondence is an unworkable proposition because there is nothing known or experienced beyond one's experiences to which correspondence can be made.
That which human beings experience consists of experiences and comprises neither causes of experiences nor independently existing objects.
There exists no evidence whatsoever of the existence of anything except one's own experiences. There exists no evidence whatsoever of the existence of causes of experiences or independently existing objects having the same evidential quality as one's own experiences.
Within the context of experience, moreover, both existence and meaning are functions of desire. I cannot be aware of anything which does not affect my state of desire in at least some way. Nothing can be said to exist that does not affect my state of desire in at least some way. I cannot verify, report upon, communicate about or do anything with respect to anything about which I have no desires at all. Desire defines meaning, existence and truth.
Understanding existence, meaning and truth as functions of desire does nothing deleterious to the concepts of correspondence, aboutness or causality. The concerns cited in the previous essay are inherent and have been there all along. They are the classic philosophic problems of solipsism, mind-matter dysjunction and that of supposed-but-never-proven independent existence. They count among the most fundamental reasons for which this philosophy forum exists. They are the very same problems about which we keep trying to achieve satisfactory states of understanding.
As for disagreement, one person desiring to do one thing in a given context while another wishes to do something else constitutes disagreement by anyone's measure. To talk about truth here is superfluous. Truth is a derivative concept which need not even be introduced when one speaks on fundamental terms. I do what I want. You do what you want. No only that, but in fact I will do what I have sufficient desire to do and you will do what you have sufficient desire to do and neither of us will do what we don't have sufficient desire to do the truth be damned. How so? Because truth is a derivative concept secondary to desire. Desire is more fundamental than truth. Desire defines truth. Truth outside of the context of desire is meaningless and worthless. Like currency without value. It's pointless.

What do you think of the "Gospel of Judas." How much more ancient wisdom is still hidden?

Truth does matter. However, truth is of relative importance and should be considered so. There are truths and truths. It may be true that your neighbor is a veteran who lost a leg in Iraq. But this truth is of importance to only a few people. That many nations are at war and killing others is another truth. This is of slightly greater importance than the previous example.
However, I have concluded after long years of study and serious contemplation of what I have learned both from books and the world around me, that the answers to the things which have perplexed mankind throughout his history and today have simple answers if we take the obvious path of commonsense and do not allow ourselves to be sidetracked by issues of little or no importance.
There are fundamental truths which come first in importance, after which we should can consider the lesser truths.

Reply: Correspondence vs. Serviceability for Desire
Are there criteria we can apply to decide which is best among alternative theories of truth? I think there are at least three. First, there is a descriptive criterion: does a theory of truth describe all (and only) instances of truth? Second, there is a normative criterion: does a theory of truth express what is right and wrong, good and bad, obligatory and forbidden, with regard to truth? Third, there is a prescriptive criterion: does a theory of truth provide instructions for how to find the truth?
Let's consider the descriptive criterion first. Does a theory of truth describe the world? Consider Mr. A, who learns that he will most likely die very soon, perhaps from some disease, or by the order of some judge. The correspondence theory of truth handles this by identifying a sentence, 'Mr. A will soon die.', and asserting that this sentence corresponds with reality. The serviceability-for-desire theory of truth, however, has difficulty identifying the sentence 'Mr. A will soon die.' as true. Is it true for Mr. A? Only if he desires to believe that he will soon die. Perhaps he does desire this in some cases; but we'll agree that in the vast majority of cases Mr. A desires not to believe that his death is imminent. So for the serviceability theory, in the vast majority of cases the sentence 'Mr. A will soon die.' is false for Mr. A, even though it's true ex hypothesi. The serviceability-for-desire theory fails to correctly sort between true and false sentences, and thus fails the first criterion test.
Now let's consider the normative criterion. Does a theory of truth express what is right and wrong, good and bad, obligatory and forbidden, with regard to truth? The correspondence theory holds that Mr. A can rightly be said to have knowledge only if his belief corresponds with reality. Mr. A can rightly be said to know the sentence 'Mr. A will soon die.' is true only if it really is the case that he will soon die. The serviceability-for-desire theory, however, holds that Mr. A can rightly be said to know only if the truth of the sentence 'Mr. A will soon die.' is serviceable with respect to Mr. A's desire. Again, in the vast majority of cases Mr. A will desire to believe that he will not die soon. But according to the serviceability theory, he can rightly be said to know that he will soon die only if he desires to believe that he will soon die. If Mr. A desires to believe that he will not die soon, then according to the serviceability theory he can't rightly be said to know that he will soon die! So the serviceability-for-desire theory of truth fails this second test.
Finally, let's consider the prescriptive criterion. Does a theory of truth provide instructions for how to find the truth? The correspondence theory holds that in order to find the truth -- in order for Mr. A to decide whether or not to believe he will die soon -- one must examine reality. The serviceability-for-desire theory, however, claims that in order to find the truth, one must examine one's desire. In order for Mr. A to decide whether to believe he will die soon, he must figure out whether he desires to believe it. Again, we agreed that in the vast majority of cases, Mr. A desires to believe that he will not die soon, in which case the serviceability theory instructs him to reject 'Mr. A will soon die.' as false.
But now, a serviceability-for-desire theorist might claim that if Mr. A desires to stay alive, he must believe the truth when he is sick or facing execution, in order to take action and maximize his chance of survival. Unfortunately, the utility theorist can't do this. For in order to take this path, in order for Mr. A to believe that he is to die soon even when he desires to believe that he will not die soon, the serviceability theorist must become a correspondence theorist! The serviceability theorist must grant that there is a reality with which at least some true sentences correspond, and in relation to which serviceability for desire is ultimately determined. This is the only way I see by which a serviceability theorist can explain why Mr. A would find it useful to believe that he will soon die, even when he desires to believe that he will NOT soon die.
So, in all three cases, serviceability-for-desire fails to pass muster.
Is there more to be said about truth? You bet! However, if the serviceability theory of truth can not meet these three criteria (descriptive, normative, and prescriptive), then in my opinion it's a non-starter for serious consideration. I would ask serviceability-for-desire advocates to examine these three problems, and to offer viable solutions to them, before I write more on this topic.

With respect to the descriptive criterion test presented above, one must consider the entire context of desires and not simply a single desire in isolation. Suppose for example Mr. A has a strong desire to not die. Someone tells him he is going to die. If the source is not credible (i.e. has failed to fuflill his desires in the past) then it will probably be more fulfilling of his desires on balance to ignore the source and he will then believe he is not going to die. If the source is credible however he will find himself discontent in trying to ignore the source and he probably will go around believing he is going to die even though he wishes to not die.
(Both of these scenarios describe how Mr. A will probably comport himself regardless of what actually eventually happens as regards his dying. A source that is not credible may turn out to be correct and a credible source may be lying.)
In this case the desire to believe one is not going to die fails to overpower the dissatisfaction in believing the credible source is in error. One cannot say a priori what desire will predominate in a given individual. There are of course cases where one's desire to believe one is not going to die overwhelms all other desires and the individual rejects the view of all authorities. Such persons are said to be in denial. And here let me also say that if someone really and totally believes something then that constitutes reality and "truth" for that person and if I could experience their experiences then I suppose it would be truth for me as well. Thus if an individual who appears to me to be dying insists they are prerfectly fine even though I see their body deteriorating well if I could experience what they are experiencing maybe I would see things in a completely different manner. Maybe such persons never experience death. In the final analysis it is what they (one) experience that counts for them (one's self). "I am not dying. I am fine. You just think I'm dying." Well maybe if I could experience their universe it would be a whole different place.
It all goes back to "Reality and truth are what one experiences, not what "is" independently of one's experience, which "independent being" cannot be known.
I do not have time now to look at the other two tests. I will try to get back later, although I have a three day driving trip to Albuquerque this week!

I agree with Paul Hollander that the bit about approximations was unfortunate in that Ken appeared to be using a true approximation to illustrate the two other quite different concepts of approximate truth and serviceable falsehood. But in fact the issue of whether a proposition must be either true or false is really just a matter of how we define "proposition". If (as some do) we define a proposition as a statement which is either true or false then indeed a proposition must be either true or false. But then with that "strong" definition of proposition, "Truth Matters" is not a proposition.
Perhaps "Truth matters to me at this time" is closer to being a proposition in the strong sense, but despite my own strong sense of a unitary identity I am aware of research which shows that sense to be an illusion, so I may actually be of several minds simultaneously on the matter of whether truth matters.
But I do believe it does (at least approximately).

In advocating the serviceability-for-desire theory of truth, ses uses such phrases as "what actually eventually happens," "someone really and totally believes something," etc. Such appeals to reality indicate that the serviceability theorist has turned into a correspondence theorist! Which is exactly my point: the serviceability-for-desire theorist is parasitic off the correspondence theorist, sneaking in hidden assumptions about what reality is really like, while at the same time claiming that truth is purely a matter of serviceability. This is simply inconsistent.
If the truth-as-serviceability-for-desire advocate desires to be consistent, then he/she ought to abandon truth-as-serviceability-for-desire.
I don't deny that psychology affects belief. But truth and belief are two different things. I think the serviceability theorist is motivated by a sincere desire to acknowledge the important role that desire plays relative to belief. This is great. But I think things get confused with the additional claim that truth, and not just belief, is a function of desire.
Protagoras's words come to mind: "Of all things the measure is people: of things that are, that they are; of things that are not, that they are not."
This is trivially true so long as it is taken to refer to belief.
However, when it is taken to refer to truth, it becomes absurd.
Rather than argue the point myself, I would refer the interested reader to two philosophical classics: Plato's Theaetetus, and Aristotle's Metaphysics Book Gamma. In the Theaetetus Socrates at one point confronts the ghost of Protagoras (actually, his imagined revivified head sticking up out of the ground) over the very claim I quote above. Aristotle picks up where Plato leaves off, identifying principles such as the so-called Law of Excluded Middle (that no proposition/sentence/statement/belief is both true and false) as necessary conditions for meaningful communication.
PS: Alan Cooper -- 'Truth matters.' is a grammatical English sentence which states that truth matters. So why do you deny that 'Truth matters.' expresses a proposition?

(Replying to Paul)
I did not deny that "Truth matters" expresses a proposition - only that it satisfies a particular possible definition of "proposition". If any "grammatical English sentence" qualifies as a proposition, then "Truth matters" is indeed a proposition, but then it is not true that a proposition must be either True or False. On the other hand if a proposition must be either true or false, then I do submit that "Truth matters" is not a proposition since its truth value depends on context and interpretation.
"Flatulence transcends verbiage" is also a grammatical English sentence whose truth value depends on the context. In a certain kind of boring lecture and with an appropriate interpretation of the word "transcends" it may well be true, but in other contexts it might be false. Most people would probably agree that this is an example which shows that "truth always matters" is false, but to an innocent on death row it is probably obvious that "truth sometimes matters" is true. Without the modifier, the simple sentence "Truth matters" is grammatical but ambiguous - so not a proposition in the "strict" sense.
-Alan

I think there are three different questions to answer: (1) Does the sentence 'Truth matters.' express a proposition? (2) Which proposition does 'Truth matters.' express? (3) What is the content of a "complete" proposition?
We can answer (1) without answering (2) or (3). Does 'Truth matters.' express a proposition? Yes. Why? Because it is a grammatical English sentence.
We can answer (2) without answering (3). Which proposition does 'Truth matters.' express? The proposition that truth matters. This is simply a matter of disquotation: for any sentence S, the meaning of 'S' (in single quotes, mentioning the sentence) is that S (not in single quotes, using the sentence with a 'that'-clause). Some prefer to use double quotes instead: the meaning of 'S' is "S," where "S" is a proposition. In either case, the matter is dispensed with by means of a kind of circularity (which isn't really circular, as it hinges on the distinction between object language and metalanguage).
So far as (3) goes, I find reasonable the view that the proposition "Truth matters" already is complete. Again, one reason for this is that 'Truth matters.' is a grammatical sentence. Another reason is that it seems to portray a way the world could be, without need for further elaboration. What is the sentence about? Truth. What does it affirm of truth? That it matters. Is this a way the world could be? Yes, of course: the proposition is true if and only if it is the case that truth matters.
Now, one might argue that the proposition "Truth matters" does not really portray a way the world could be, because it never is the case that truth matters simpliciter. Truth matters only for this or that person, at this or that time, etc. Perhaps. But at this point the quibble is not over whether "Truth matters" is a complete proposition, but rather over whether "Truth matters" is true! Obviously, if we're at the point of debating whether it is true, then we've already accepted that we're dealing with a complete proposition!
Again, I think mistakes get made when problems for meaning are erroneously regarded as problems for truth.
So far as whether there are only two truth values, or more than two, I would repeat what I wrote earlier, that the simplest theory capable of accounting for our truth-talk is a theory positing just two truth values, true and false. This is not the only theory of truth; just the simplest. Of course, Occam's razor asks us to go for the simplest complete explanation, so there you go, IMHO....

Sorry Paul, I must be a bit dense. I can't help reading what you say as asserting both that every grammatically correct sentence is a proposition and that every proposition must be true or false. But the sentence "This sentence is false" does seem to me to be grammatically correct. What am I missing?

Great point!!!! The sentence 'This sentence is false.' seems to be grammatically correct, but if we take it as expressing a proposition, we run into problems because if 'This sentence is false.' is true, then it is false, and if it is false, then (given only two truth values) it must be true. A paradox!
We have two options. We can either bite the bullet and admit that 'This sentence is false.' expresses a proposition, with all the problems which that entails. Or we can reject 'This sentence is false.' as not grammatically correct, and so not expressing a proposition. But this also entails problems because it leads to the question, on what basis do we reject it? On a syntactic basis? But it's syntactically correct. On a semantic basis? But if we're going to introduce semantic distinctions here, why can't we do the same with the sentence 'Truth matters.'? Or other sentences as well?
The solution I find most plausible is that we reject 'This sentence is false.' as being grammatically incorrect. What distinguishes this sentence from 'Truth matters.' is that, if we admit 'This sentence is false.' as a grammatical sentence, we violate the Law of Excluded Middle, which holds that no proposition is both true and false. We do not violate Excluded Middle if we admit 'Truth matters.' as grammatically correct.
This is no trivial matter. I, for one, am quite willing to consider possibilities that do not violate Excluded Middle, but I'm not willing to do this regarding possibilities that do violate Excluded Middle. So I can accept 'Truth matters.' as meaningful, but not 'This sentence is false.'. I suspect most people are in the same boat.
Notice that similar problems arise when we consider other kinds of sentences. 'I'm male.' is true only when spoken by about half the population. So how can 'I'm male.' express a proposition? 'I'm laughing now.' is true sometimes when I use it, false other times. Such issues take us into the domain of philosophy of language, which can get very complicated.
In general, we use sentences to make statements which assert propositions. We talk in shorthand about sentences expressing propositions, but that's a standard assumption when dealing with the formal properties of language, in which case we typically assume that there are no ambiguous sentences. (This assumption is not a problem as it can be set aside at any time.) Propositions themselves are intentional objects, which means we do not have direct perceptual access to them. We only get at the structure of a proposition by symbolically representing it. We can make maps of propositions in the form of sentences, but we can never see, hear, touch, taste or smell propositions themselves. And yet we know propositions exist because we cogitate in terms of them. This state of affairs means we are stuck using language in order to examine the structure of the proposition, with all the difficulties that entails.

Well then, to me, I guess "Truth matters" is not a
"complete proposition", but we may be taking this discussion off topic with our focus on whether the excluded middle is or is not a "grammatical" rule.
Getting back closer (I hope) to the point of what I think Ken was saying in his original posting, I would suggest that his emphasis was more on the need (or not) for avoiding untruth, rather than on finding value in every true statement. Sometimes the truth of a matter really does NOT matter or is best not known, but perhaps there is a stronger case for the thesis that "UNtruth matters". ie that it is almost always wrong to believe or assert that which is demonstrably false. (And perhaps the specific theory of truth being applied is less relevant if we restrict to the "demonstrable" situation where correspondence and convention coincide.)
So the question becomes under what circumstances may a falsehood not be a bad thing.
The finding of value in a "serviceable falsehood" of the kind exemplified by "Saddam had WMD", (as used to motivate soldiers into having a sense of purpose which may have enhanced their effectiveness), is however not related to any particular property of truth or falsehood. It is rather just another example of an "ends vs. means" issue, perhaps analogous to the argument of net utility that may be used by some in the familiar moral exercise of deciding whether or not to push someone off a bridge in order to block a train which would otherwise run over several people standing on the track. To some, doing wrong to produce an eventual good result can never be justified, but many others accept the net utility argument. For example many of us who would not push the fat guy off the bridge to block the train from running over the kids will regularly and willingly support minor injustices for some on the basis of serving the greater good (eg a not entirely equitable tax law for which the fairer alternative would be more expensive to administer). But even those would probably agree the small injustice is wrong "in and of itself", and should be avoided if the same general gain could be achieved in some other way. Similarly, the possible net value of a "serviceable falsehood" does not contradict the fact that promoting the falsehood is ("morally") wrong in and of itself. But anyhow, as I said at the beginiing of this paragraph, this aspect of the issue has nothing to do with the particular issue of Truth per se.
So my question is: Is there more to the idea of "serviceable falsehood" than this?
Scientific theories are often described as serviceable falsehoods which we accept for lack of a better alternative. This is what I believe Ken was getting at, although his reference to "approximate truth" may have led some of us astray. One view of a scientific theory is as something which claims only to compactly "predict" the results of all past observations (at least to within the accuracy range with which those observations were made). As such, if successful, the theory is true so long as its predictions all fall within the error bounds of the corresponding observed measurements. But when the theory is used to predict future observations, then it runs the risk of being falsified - as all theories will be (at least for so long as science continues to be worth doing). But "falsification" of a theory doesn't always make it false. Often, as in the case of Newtonian mechanics, it just puts restrictions on that theory's domain of validity.
An important distinction here (which appears to escape the compehension of many non-scientists) is between two entirely different notions of scientific 'theory'. One, like Newtonian mechanics or its various relativistic and quantum sequels, is a set of rules (generally expressed in mathematical formulae) relating various observed values, and the other is an explanation of some phenomenon in terms of a higher-level theory of the first kind. The statistical mechanical explanation of thermodynamics is an example of the latter, as is also just about every theory of astronomical or biological evolution.
It is in the latter case (of "theories" which purport to explain some observation) where, to a scientist, "truth" is actually at issue and "matters" (no matter whether anyone else actually gives a damn). There really is only one true answer to the question of how our solar system originated, and most scientists expect that eventually we will find sufficient evidence to confirm one such theory. The same applies to various questions about how certain steps in the evolution of current species occuurred, but although one would have to be a complete idiot to suggest that there is no possibility of finding a purely mechanical path from non-life to the current situation, there are certainly cases where we do not yet know which "theory" is correct. And, yes, to those of us who care, it does matter a lot. (I don't know if Alexander Keith's Pale Ale is advertised in the US, but the tag-line is "Those who like it like it a lot" and perhaps the situation is similar.)
However a wrong theory of planetary or biological evolution is not a "serviceable falsehood". It is just plain wrong as a history of events, and it will eventually be found to conflict substantially with some observed fact to an extent not within the bounds of experimental error (and probably not even within any limited bounds that corresponded to the measurement capabilities of science at the time the theory was proposed).
Another kind of "serviceable falsehood" is promoted by some "enlightened" religious leaders. The thesis seems to be that the literal truth (or more probably untruth) of their scriptures does not matter because of some "deeper" meaning that belief in them is deemed to facilitate. This is of course, like every other religious doctrine in human history, a total pile of unholy evil crap. (I have a truly marvelous proof of this proposition which this blog comment is unfortunately too brief to contain.)

I think the significant question is, can we get the benefit of knowledge without actually possessing knowledge? Or is there some benefit we get from knowledge, that we can only get from knowledge? This I think is the gist of the problem Ken posed. For, if we can get the benefit of knowledge without actually possessing knowledge, then perhaps our belief about the value of knowledge is mistaken.
I believe there is value that we get from knowledge, and that we can only get from knowledge.
If we know a proposition is true, then we have good reason to believe any proposition entailed by that proposition -- and it will also be true. If I know that the cat is on the mat and that all cats are animals, then I have good reason to believe that an animal is on the mat -- and furthermore it will be true that an animal is on the mat.
No other kind of belief does this. Belief that is merely true gives no good reason to believe anything; while belief for which we have good reason, but that isn't true, might give good reason to believe something, but without any guarantee that this something is actually true. It's only when we have both good reason and truth that we have the unique benefit conferred by genuine knowledge.
Those who disagree are in the position of having to find some counterexample, some belief that does not constitute knowledge, but that nonetheless does give good reason for believing any logical consequence of the belief -- and guarantees that it will be true. I don't think this is possible. I'd like to hear of any examples that anyone comes up with. I don't think they exist. I hereby throw down the gauntlet and set the challenge for someone to come up with a counterexample!

I made it to Albuquerque and have found some time to return to this discussion.
Paul Hollander above offers the criticism that my phrases "what actually happens" and "someone really believes something" are inconsistent with the position that truth is defined by desire. There is no inconsistency. The identity of "what actually happens" is determined by one's experiences and that is all that is known. "Someone really believes something" says just what it says and nothing more. One believes what one believes. That one believes or knows something does not mean one knows anything about anything else.
(Relative to his criticism he suggests I abandon my position "in the interest of consistency". I'm sure abandonment would please him in any eventuality but I'm hardly going to throw out a beautiful baby in pristine water just so he can populate the earth with his own flawed progeny.)
(Paul I can't even say your effort was credible. In the interest of morality however I will grant to you that "what actually happens" is a misleading use of words, nevertheless, not fundamentally a matter inconsistent with my position. There may, or may not, exist independent entities. One has this impression they exist for various reasons. But they may not exist. If they do exist one has no verification of their existence independent of one's experiences. Even if they do exist they do not matter except in the capacity of their being experienced.)
Going back to the last two "tests" he proposes above which I did not have time to address earlier, both the "normative" and "prescriptive" considerations are readily dismissed in that desire understood as the foundation of truth obviously and easily accounts not only for what one views as good/bad and right/wrong but also true/false.
We're right back where we started. One experiences that which one experiences and has no other knowledge of independent or objective entites or causes of experiences. Within the context of experience, states of desire determine what is considered true or false. No one has said anything having any substantiality to incline one otherwise.

One more point. In the above post I talk about the relation between truth and knowledge. Knowledge entails truth.
But not the other way around: truth does not entail knowledge.
Some might claim that if we don't or can't know that a proposition is true, then that proposition is not, in fact, true. This is what happens when truth gets defined as "warranted assertability" or some such thing. Is 'God exists.' true? No. Is 'God exists.' false? No. 'God exists.' acquires a third value, neither true nor false, because we are never warranted in asserting either that God exists or that God does not exist.
This presents difficulty.
Consider a legal system in which not only the plaintiff must prove she knows the charge to be true, but also the defendant must prove she knows the charge to be false, in order to win the case. If neither side can do this, then the case never gets resolved. Plaintiffs have the advantage because the mere leveling of a charge -- especially one that can't possibly be resolved -- can place a defendant in legal limbo literally forever.
This might sound to some like an accurate description of our situation. But think about it. Our president makes outrageous claims. If there really were three truth values, and if a proposition really were true only if we knew it was true, then we would be at a severe disadvantage when disputing the president's outrageous claims.
Just like the hapless defendant in the above example, we would have to prove we knew that the president's outrageous claims were false, in order to resolve the issue. Maybe we can't do that. Maybe at best all we can do is cast doubt on the verity of the president's outrageous claims, without proving we know them to be false. If so, then we are stuck. The president could make outrageous claim after outrageous claim, and in each case we would have to prove we knew the outrageous claim was false in order to resolve things. Obviously, those who make the outrageous claims have the advantage, while those casting doubt on the outrageous claims of others are at a clear disadvantage.
Is this the kind of world we want? Not me. It places the vast majority of us at the mercy of a powerful few, ensuring that the strong, who can shout the loudest and have the most to gain from outrageous claims, will do what they can and the weak, the rest of us, will suffer what we must.
For myself, I prefer a more equitable conception of truth. The only way to get that is for truth to be independent of knowledge. There are truths that we don't and can't ever know. They exist. If they did not exist, we should be in a very grave situation indeed.

ses: I'm not sure you understand my criticism.
The claim that truth is a consequence of subjective desire has been criticized for erroneously relativizing truth: what's true is only ever true for me, or true for you, or true for whomever; there is no truth independent of being true for someone. As I have already pointed out, this eliminates the possibility of genuine disagreement. We can't ever disagree without truth that applies equally to you and to me. You deny that genuine disagreement exists because you claim truth is relative to each person. This places you in the onerous position of having to convince us that disagreement is merely illusory. At this point, who looks more ridiculous, you or me? You're the one denying that disagreement (or agreement, for that matter) is real!
You also deny that you're contradicting yourself when you are caught red-handed. You claim that truth is relative and subjective, and yet at certain key points you claim that truth is not relative, not subjective, because you wish to talk about reality, and about what really happens. Well, which is it? Is truth relative and subjective, or isn't it?
So not only do you deny something that this very discussion proves is true -- that disagreement is real -- but you blatantly contradict yourself while you are doing it, and then deny that as well!
As if this weren't enough, ses, you also prevaricate about the nature of your claim. Sometimes you talk about what's true; other times you talk about what is considered to be true. When you wish to capitalize on the objective nature of truth, you talk about what's true. But when you wish to emphasize the alleged subjective nature of truth, you talk about what's considered to be true. Well, which is it? Are we talking about what's true, or are we talking about what's considered to be true? These are not the same thing.
Again, it's not clear to me that writing more on this myself is helpful. I refer you to the Theaetetus and to Metaphysics Book Gamma. Perhaps Plato and Aristotle will provide you with a more entertaining opponent.
Of course, all this can be settled in an instant by asking just one key question: does ses speak the truth? Think about it....

I'm pressed for time again. I hope the following is clear. It will have to suffice for the moment.
Paul it seems to me it's all very simple. People believe things when they have sufficient conviction and act when they have sufficient desire. Things do get done -- and that's how they get done. One doesn't conceptually need absolute truth for it to happen. I do consider that the reality is that nothing can be absolutely proven and everything is an apparent power struggle. An interplay of desires on an intra- and inter-personal level (if any other conscious beings really exist.
And having at one's disposition "absolute truth" gets one nowhere because then the other side just claims it has absolute truth. And the fact is --and this is important and supports my whole position -- if I really believe or feel that what I believe is absolute truth then it functions as such for me no matter what "reality" is. We just don't really know what's going on as far as I'm concerned.
"I think therefore I am" = "From my standpoint what I am experiencing constitutes reality. This is as real as I know it. I have no experience or knowledge of any other existence or reality"-- along with the subjective assessment "and/but this is overall a qualitatively very unsatisfactory situation"!
We do agree the "President" makes outrageous decisions. Things are in a really sorry state and we may be headed for very dark days owing to really national incompetence. Not that I blame anyone. I don't "believe" in blame as such.

Paul my last post does not address your last post it was written beforehand. I'm out of time for today. I already addressed the issue of disagreement above read it again. Truth is a function of what matters to the conscious entity in question. What matters to the entity in question depends on the desires of that entity.

I get the feeling that, because I hold a desire-independent view of truth, somehow I'm getting accused of being a dogmatic absolutist.
Which is more democratic? To believe that we can always appeal to a concept of truth independent of values, interests, desire, power, and the like? Or to deny that belief?
We who advocate independent truth are in favor of the right to question anything, free of restraints about what's in anybody's interest, what conforms with anybody's desire, what serves anybody's values, etc. This seems to me to be a basic human right. Certainly Socrates would have approved! It would be a shame if the Truth Police confiscated it.
Unfortunately, whether they realize it or not, the peddlers of truth-as-a-consequence-of-_____ (fill in the blank -- desire, values, whatever) are opposed to this fundamental right, because for them there is no independent truth, only truth relative to _____. On their account, we are never free to consider truth independently of _____, and it's just plain wrong to believe we can.
Again I ask, which is more democratic? Our basic human right to question without restraint? Or parading forth _____ as the final determinant of all truth, regardless of what anybody else says?
You be the judge.
But hurry, before the Truth Police take away your right to decide free of _____!

If you're questioning everything you're not asserting the existence of independent truth. If you're asserting the existence of independent truth you're not questioning everything.
To assert the existence of absolute truth obviously is as much an imposition as to assert that what is called truth can be understood as derivative. And the company kept relative to the former assertion inspires considerably less confidence.
To assert what actually is the absolute truth obviously is to question nothing. It is to accord no right to anyone else.
To assert the existence of absolute truth that is totally inaccessible is pointless.
The Thought Police have arrived but they're not making any sense.

ses, your error, other than trying to use elaborate grammar to try to give your assertion weight, is that you ignore or are unaware that the purpose of LIFE is to LIVE. (Supersets trump subsets in this, thus the individual's purpose is to propel the organism, whose purpose is to propel life itself (not all life).)
Paul is correct in that the de facto rulers, of the empire we reside in, know that if they trick us to think that truth is relative, always based upon some variable, then they can control the truth. They only have to choose variables that they believe they can control and have no chance for us to effect (ie: ""terrorism"").

Why do we need to know truth?
I?ve heard it many times that ?truth will set us free? and that sounds biblical.