Is it reasonable to conclude that Nessie doesn’t exist? For those of you living in your basements, Nessie is the nickname given to the mythical(?) Monster of Loch Ness in Scotland. There have been many, many sightings of Nessie since the first modern sighting of Nessie in 1933, and several photographs apparently depicting something in the water have been shown, but still people doubt that Nessie really exists. Why?
I can give several reasons to doubt Nessie’s existence, but perhaps the main one is that the Loch Ness has been searched rather thoroughly by sonar, and these sonar searches failed to turn up any sign of a large, prehistoric monster living in the waters. As reported in the Skeptical Inquirer:
In July 2003, a team commissioned by the British Broadcasting Corporation to search Loch Ness for its fabled monster concluded that Nessie could not be found.
Though the lake has been searched repeatedly over the past seventy years, the investigation is the most thorough to date. The BBC team surveyed the waters using 600 separate sonar beams, and used a satellite navigation system to make sure that the entire lake was searched.
Ian Florence, one of the experts who participated in the investigation, was emphatic that the lake holds no monsters. "We went from shoreline to shoreline, top to bottom on this one, we have covered everything in this loch and we saw no signs of any large living animal in the loch."
Of course, the people who believe in Nessie’s existence haven’t given up hope that the monster still exists despite this extensive search. Some argue that there are a series of caverns below the Loch Ness that could harbor the monster when it is not swimming in the waters. But skeptics don’t find this argument very compelling – it seems more wishful thinking than fact.
An Appeal to Ignorance?
Are people wrong for doubting that the Loch Ness Monster exists? Some would say that the argument against Nessie's existence is an appeal to ignorance. The fallacy of appeal to ignorance, aka Argumentum ad Ignorantiam, takes two forms, the second of which can be described in the following syllogism:
There is no evidence for X.
Therefore, not X.
Are the people who doubt the existence of the Loch Ness Monster guilty of committing this fallacy? Are they saying, "there is no evidence for the existence of the Loch Ness Monster, therefore the Loch Ness Monster does not exist"? If a person concludes that it is a fallacy, then that person is failing to make a distinction between the informal fallacy of Argumentum ad Ignorantiam and valid inductive reasoning. As noted in Logic (2nd Ed., p. 126):
Some arguments may appear on the surface to commit the ad ignorantiam fallacy, but on closer inspection can be seen to be legitimate. In particular, certain inductive arguments are quite good, even though they appear to have the same form as an ad ignorantiam fallacy:Every possible attempt has been made to prove that such-and-such is the case.
Not one attempt to prove that such-and-such is the case has been proven successful.
Therefore, it is probable that such-and-such is not the case.
This is essentially the type of reasoning that some physicists used at the end of the nineteenth century in arriving at the conclusion that a gravitational aether does not exist. It is probably also the kind of reasoning that led to the demise of alchemy. The conclusion that a base metal, such as lead, probably cannot be turned into gold was not unreasonable in the seventeenth or eighteenth centuries, even though present-day theories indicate that such a transmutation is at least theoretically possible. In any case, when confronted with an argument that appears to involve the ad ignoratiam fallacy, we should make sure that it cannot reasonably be interpreted as being a possibly good inductive argument.
Obviously, good inductive arguments are never certain. At best, they can only say that "based upon thorough observations, such-and-such is almost certainly true." To come to that conclusion following a reasonably thorough search is not committing the ad ignoratiam -- it is practicing good, valid inductive logic.
Nessie and the Lost Goldmine in the Superstitious Wilderness
Consider Dr. William F. Vallicella's Maverick Philosopher entry of September 6, 2005:
But consider this example (mine, not Larmer's):
1. If there were a lost goldmine in the Superstition Wilderness, then, given the extensive and protracted search operations of generations of 'Dutchman hunters,' it would have been found by now.
2. No goldmine has been found in the Superstition Wilderness.
3. There is no lost goldmine in the Superstition Wilderness.
This is a valid argument: the conclusion follows from the premises by modus tollendo tollens. Since premise (2) is true, the soundness of the argument rests on whether (1) is true. Now (1), though not obviously true, is certainly plausible since there is positive evidence for it. The evidence is not merely that no one has discovered the mine, but includes the fact that the geology of the region makes the existence of gold deposits unlikely. Since there is positive evidence for (1), we do not have here an appeal to ignorance.
Note that (1), though a conditional, need not be interpreted as a truncated argument; so it is unavailing to look for the ad ignorantiam fallacy within the bosom of (1).
The argument (1)-(3), then, is pretty good: it is valid in point of logical form, and its premises are reasonably accepted. It is an argument I would lay money on. If there is any problem with the argument it does not reside in its logical structure, but in the truth-value of its initial premise. So there is no question of a fallacy (in the logical sense) having been committed.
In the case of Nessie, the 2003 sonar search turned up no sign of Nessie. Is it irrational to conclude that Nessie doesn’t exist? Plugging in the Nessie situation into Dr. Vallicella's syllogism, it reads:
Premise 1: If there were a prehistoric monster living in the Loch Ness, then, given the extensive and protracted search operations by the BBC, it would have been found.
Premise 2: No prehistoric monster has been found in the Loch Ness.
Conclusion: There is no prehistoric monster in the Loch Ness.
This is not a logical fallacy but an inductive argument. It is reasonable to believe that there is no monster in Loch Ness based on the thorough sonar search. This does not mean that the monster is necessarily not there. It is possible that it escaped the search by living in an underwater cavern that kept it from being detected. But saying that it is reasonable to believe something by inductive logic always has some element of uncertainty of the absolute truth of the underlying proposition.
ID is a God of the Gaps Argument?
So, why am I saying all of this? Well, the September 30 entry of Bill's List references a blog named Slate which has an entry by some not particularly clear-thinking individual named Dahlia Lithwick entitled "Mind of the Gaps: Intelligent design as an answer to all life's great conundrums". As Bill's List notes, Lithwick's entry "completely misunderstand[s] (I'm being charitable and not saying ‘misrepresent[s]’) [the theory of Intelligent Design (ID)]. Lithwick treats ID as a God-of-the-gaps argument." Here is what Lithwick says:
[T]he really great thing about intelligent design is that it takes all the awkward uncertainty out of science. It says, "You know those damn theoretical gaps and conundrums that send microbiology graduate students into dank basement laboratories at 3 a.m.? They don't need to be resolved at all. Go back to bed, sleepy little grad students. God fills those gaps."
Let's face it: The problem with science has always been that each new discovery unleashes thousands of new questions and ambiguities. So really, the more we discover new stuff, the stupider we get. Clearly, that isn't working. ID says we shouldn't bother ourselves with resolving scientific inconsistencies or untangling puzzles. We should recognize that what God really wants is for us just to stop learning.
Think of the applications. Science is, after all, teeming with unresolved conundrums. What if we just recognized, for instance, that we can't make the Standard Model of particle physics work? This theory, which purports to describe all known matter—including subatomic particles, such as quarks and leptons, as well as the forces by which they interact—is plagued by scientists' failure to observe something called "proton decay." Now, if we apply the ID principle to particle physics, no one ever needs to put on a lab coat again. Quarks and leptons? They're made of God.
This view of ID is not atypical. It is actually a rather common warping of the view of ID by claiming that it appeals to the God of the Gaps, therefore committing the logical fallacy of the appeal to ignorance. In other words, this "God of the Gap" claim is that ID argues, "There is no evidence for a naturalistic rise in complexity in the most basic of all living cells, therefore the complexity in cells did not arise naturalistically." But that is not what the ID proponents are saying. They are making a valid inductive argument:
Premise 1: If there were a purely naturalistic explanation for the complexity that we see in even the simplest of living cells, then, given the extensive and protracted research by generations of scientists, it would have been found by now.
Premise 2: No purely naturalistic explanation has been found for the complexity that we see in even the simplest of living cells.
Conclusion: 3. There is no purely naturalistic explanation has been found for the complexity that we see in even the simplest of living cells.
Moreover, as noted by Bill's List, the ID proponents go beyond this inductive argument alone. They also make the positive claims, to wit:
(1) the work of intelligent agents has certain earmarks, which (2) we are capable of recognizing, and (3) those earmarks are on display in some scientifically-investigated phenomena.
In no way are the advocates of ID committing the ad ignorantiam fallacy. They are not arguing for a God of the Gaps. Rather, like the BBC researchers at Loch Ness they are saying that a thorough search of the field has not turned up any evidence for a naturalistic explanation for the rise of even the simplest of living cells due to the immense complexity study of these cells has revealed. On that evidence, it is reasonable to infer that such a naturalistic explanation did not occur and we need to investigate more thoroughly the possibility that design played a larger role than the Darwinists would care to acknowledge. In that area, ID proponents are seeking to identify the earmarks of design.
Where does that leave the Darwinists? Well, if the advocates of ID are right and that the lake of possible purely naturalistic explanations has been searched relatively thoroughly, then the Darwinists are the Nessie-apologists arguing that she is hiding under the surface in some undiscovered cave. Possible? Of course – but contrary to the presently existing best evidence.