What's the big deal with tautologies?

[QED]

The myth of evolution is easily falsified by cognitive scientists, since it is nothing but a tautology consisting of circular reasoning within more circular reasoning.

The Theory of Evolution is an unfalsifiable Tautological Theory, akin to UFO's and their intergalactic proctologists.

It sounds like you are mixing the theory of evolution up with the tautology of natural selection.

Often I hear natural selection being put down by calling it a tautology. I suspect the general idea is to attempt to render "survival of the fittest" meaningless by this accusation.

As far as I'm aware Tautology gets a bad name through being a stylistic transgression, by introducing redundancy into a statement, i.e. stating the same thing twice like Windows 2000 - based on NT Technology (New Technology Technology). Now survival of the fittest may be describing an obvious consequence to most people, but dropping either the verb or the subject would rather suggest that neither were redundant. Perhaps the whole expression is thought to be redundant in that it states the obvious? But what about: misery of the oppressed, joy of the blessed, extermination of the executed. Are these consequences devoid of all meaning too?

What am I missing? (asked with a genuine 50/50 expectation of being put right)

[McCulloch]

A tautology can have the rhetorical sense of being a meaningless repetition. Examples, the Department of Redundancy Department, ISBN numbers, GOP party or the NDP party, free gift, new innovation, tuna fish, .

But tautology also has a related meaning in logic. A compound propositional form all of whose instances are true, as “A or not A.”

This candidate will win or will not win.

Anything that happens, happens. Anything that in happening causes something else to happen, causes something else to happen. Anything that in happening happens again, happens again. Though not necessarily in that order.

[QED]

But tautology also has a related meaning in logic. A compound propositional form all of whose instances are true, as “A or not A.”

Very good. I expect this is the category of tautology that survival of the fittest falls in. Fittest, we must understand, does not mean physically fit -- as in certain evolutionary situatuaions fitness may be identified with physical weakness (worth mentioning as frequently as possible to deflate a common creationist misconception).

This candidate will win or will not win.

Anything that happens, happens. Anything that in happening causes something else to happen, causes something else to happen. Anything that in happening happens again, happens again. Though not necessarily in that order.

Isn't there a difference between these two examples?

[Fisherking]

Often I hear natural selection being put down by calling it a tautology. I suspect the general idea is to attempt to render "survival of the fittest" meaningless by this accusation.

What does survival of the fittest actually explain? If we were to ask who in a population would survive, we would say the fittest. If we were to ask who are the fittest individuals in a population, we would say the survivors.

Tautologies are fine as definitions, but not as testable scientific statements -- there can be nothing in test in a statement true by definition (Gould, Darwins Untimely Burial-Again! 1983, p.141)

As far as I'm aware Tautology gets a bad name through being a stylistic transgression

Tautologies give the mistaken appearance of conveying knowledge. Yet they are neither explanatory nor testable, so they are not science. They are dangerous because they masquerade as knowledge, while conveying no useful information. Tautologies are most dangerous when they are unobvious and thereby escape our detection. In such cases, we must unmask the tautology by plugging in the defintions of the words. Then the circular definition of a tautology becomes clearer.
.....Another objection is that tautologies are not falsifiable. They are always true... by definition. There is no concievable observation that could refute a tautology. Tautologies are not testable. (ReMine, The Biotic Message, p 98)

[QED]

Thanks for the definitions McCulloch and Fisherking.

Right, so the kind of tautology that "survival of the fittest" is supposed to be is not of the type that has a redundant term in the statement (e.g. ISBN Number) but is of the compound propositional form all of whose instances are true, as in “A or not A.” (This candidate will win or will not win"). In this case the whole statement is redundant as it tells us nothing of any use.

So we can agree that tautologies of this kind might "give the mistaken appearance of conveying knowledge. Yet they are neither explanatory nor testable, so they are not science." As ReMine puts it.

But I'm not at all satisfied that "survival of the fittest" is truly a tautology of this kind. When Gould says "Tautologies are fine as definitions, but not as testable scientific statements -- there can be nothing to test in a statement true by definition" he makes it clear that what makes a statement useless is through being true by definition and not being testable.

Fine. Can we subject survival of the fittest to a test to see if it's true or if it's false? At first blush it might seem that we can't because what survives is what we call the fittest -- but that isn't necessarily the case. We can always look at the various candidates in advance and, use our knowledge of "racing form" to predict what the fittest would be. If these are the ones that survive, then the hypothesis is confirmed. If not we have to start looking around for an alternative.

I would have thought that the theist would be eager to step in with such an alternative as, in a world dominated by a divine interventionist, survival might not be dependant on fitness anyway. After all Isn't it supposed to be the meek that shall inherit the Earth?

BTW, ultimately Gould doesn't think survival of the fittest is a tautology. Read the five paragraphs that follow the one Fisherking quoted above and you'll see why.

[Furrowed Brow]

Fine. Can we subject survival of the fittest to a test to see if it's true or if it's false? At first blush it might seem that we can't because what survives is what we call the fittest -- but that isn't necessarily the case. We can always look at the various candidates in advance and, use our knowledge of "racing form" to predict what the fittest would be. If these are the ones that survive, then the hypothesis is confirmed. If not we have to start looking around for an alternative.

But if we choose the wrong set of characteristics then we'd say something like those features we not so fit - nature knew better. Or some such. I don't think this is the way to escape tautology.

Here is a very simply formalisation of the problem

Survival fitness quotient = (Existing DNA + mutation) * environmental changes / established environment

Now the "survival of the fittest" can be expressed in such a way that requires empirical input. And anything that is based on empirical observation is not a tautology. However if someone could come up with a perfect formula that always gave the correct result then it might be argued that such a formula was true a priori and thus a tautology. However the out put from the formula will still depend on empirical observation, so the out put would never be a tautology.

[QED]

But if we choose the wrong set of characteristics then we'd say something like those features we not so fit - nature knew better. Or some such. I don't think this is the way to escape tautology.

Except that if instead of nature, it was some kind of "supernature" that confounded our predictions (i.e. a miracle) then our test would confirm something we might not have expected. Of course for those who would favour the miracle, the test might confound their prediction and confirm natural selection. So, it still looks like a valid scientific theory to me and one that could identify supernatural intervention if it was taking place.

Here is a very simply formalisation of the problem

Survival fitness quotient = (Existing DNA + mutation) * environmental changes / established environment

Now the "survival of the fittest" can be expressed in such a way that requires empirical input. And anything that is based on empirical observation is not a tautology. However if someone could come up with a perfect formula that always gave the correct result then it might be argued that such a formula was true a priori and thus a tautology. However the out put from the formula will still depend on empirical observation, so the out put would never be a tautology.

Let's see what our ID friends have to say now we've rid survival of the fittest of it's tautological put-down!

[Undertow]

If you look at the fittest as merely those who survive then of course it will be tautological. Isn't this based on how you define the fittest? For example if I expect that allele 'x' for gene 'y' is the fittest, I would need to wait and see the outcome where my expectation could be validified or thrown out. Instead of a retrospect view of 'this trait adds fitness because it's managed to survive and it managed to survive because it was the fittest' you should, if you wanted to do something scientific with the idea, hypothesise which trait or character will add fitness.

[Goat]

If you look at the fittest as merely those who survive then of course it will be tautological. Isn't this based on how you define the fittest? For example if I expect that allele 'x' for gene 'y' is the fittest, I would need to wait and see the outcome where my expectation could be validified or thrown out. Instead of a retrospect view of 'this trait adds fitness because it's managed to survive and it managed to survive because it was the fittest' you should, if you wanted to do something scientific with the idea, hypothesise which trait or character will add fitness.

Or, you could change that definition as those that are able to reproduce better.

[Fisherking]

If you look at the fittest as merely those who survive then of course it will be tautological. Isn't this based on how you define the fittest?

Yes

Here is a very simply formalisation of the problem

Survival fitness quotient = (Existing DNA + mutation) * environmental changes / established environment

Now the "survival of the fittest" can be expressed in such a way that requires empirical input. And anything that is based on empirical observation is not a tautology. However if someone could come up with a perfect formula that always gave the correct result then it might be argued that such a formula was true a priori and thus a tautology. However the out put from the formula will still depend on empirical observation, so the out put would never be a tautology.

In contrast, a tautology is essentially a logical argument or proposition of causation (or, if you prefer, premise and conclusion) with two parts: (1) an if . . . then . . . relationship, such as If A, then B, coupled with (2) a definition of A (the cause or the premise) by reference to B (the effect or the conclusion). This is precisely the problem that plagues natural selection as it is so often described: If the organism is fit, then it will survive; and fitness means that it did survive (or will survive, or is expected to survive, take your pick).

Let’s look again at the Newtonian equation F=ma. Even though force, mass and acceleration can be mathematically described in terms of each other, they do not cause each other. Force doesn’t cause mass; mass doesn’t cause acceleration. The mathematical equation is an equivalence statement of their relationship.

In contrast, natural selection posits a cause-effect relationship. Because of an organism’s fitness, it is theorized, the organism survived (will survive, is expected to survive, etc.). Thus natural selection is in the business of explaining what leads to or causes survival. So far, so good. But when we then seek to explain this causal relationship by defining the causative element (“fitness”) in terms of the resulting element (“survival”), we have a tautology.

I indicated that there is a way out of the tautology problem, and there is. But only if the cause, fitness, is carefully defined by reference to characteristics that are independent of the result, survival. Thus, natural selection would not be a tautology if we define fitness in terms of independent characteristics such as speed, or bodily efficiency, or reproductive capability. If we define fitness this way, then we can hypothesize that natural selection actually means survival of the fleetest, or survival of the most efficient, or survival of the most prolific. A Good Tautology is Hard to Avoid

If we do define fitness this way, we move into what ReMine calls a special definition in The Biotic Message:

A way out of the tautology objection is with a special definition. A special definition is when a theory (or keyword) is specially defined for each case.
Special definitions are made by redefining fitness for each given case, resulting in a special definition of fitness. In one instance fitness is 'cryptic coloration.' In the next it is 'high speed.' In the next it is 'small size.' In the next it is 'aggressive behavior,' and so forth. Most everything has been used in special defintions of fitness. Each instance of organism and environment recieves its own special definition

.

Survival fitness quotient = (Existing DNA + mutation) * environmental changes / established environment

Special definitions are not tautologies. Yet a theory made of more than one definition (and especially contradictory definitions) is not science. A theory cannot be tested when redifined for every case. Special definitions are a multitide of disjointed, conflicting explanations masquerading as a single, unified theory.

......In summary, special defintion are non-tautologous, explanatory, testable, and true for a narrow special case. Yet they have two drawbacks:

1) They are false for the general case.
2) They do not unify our understanding of nature in the manner claimed of
natural selection.(Remine, TBM, p102)

Unfortunately, despite all the intervening decades since Darwin, we still seem to be unable to come to any concrete working definition of fitness. This is the source of the disillusionment with the concept of natural selection expressed by so many.

The concept of natural selection as proposed by Darwin, and as often applied today, is likely a tautology. The only way for us to keep it from failing as a tautology is to carefully define fitness in terms of characteristics that are independent of survivability. And once saved from this logical precipice, the only way to give natural selection any real explanatory substance is to come up with a concrete working definition of fitness that can be tested. Although various vague characteristics have been proposed, such as efficiency, it has been notoriously difficult to pin down any useful working definition of fitness over the past century and a half. Without such a definition, we cannot carry out meaningful empirical test to determine the correctness of the hypothesisA Good Tautology is Hard to Avoid