Word of the Day: Genetic and Ad Hominem Fallacies

Christian apologetics in the big bookThe Heartland Institute recently put up a series of billboards featuring Ted Kaczynski (the Unabomber), Charles Manson (a cult leader), and Fidel Castro (a dictator). The text read: “I still believe in Global Warming. Do you?”

These are examples of the genetic fallacy. We’re asked, “How plausible can the claim of global warming be if these nutjobs accept it?” A genetic fallacy ignores any actual evidence or argument and looks instead at the origin (think genesis) of the argument. It’s a fallacy because it offers no relevant argument.

Another example would be, “You’re a vegetarian? Don’t you know that Hitler was a vegetarian?”

But consider this: “You can’t tell me that those new phosphorescent zucchinis are safe! Don’t you know that the research that supports that claim was funded exclusively by MegaCorp, the company that patented that vegetable?”

This claim is more compelling. Though it is genetic, it does more than make a simple origins claim. Compare that with “Don’t tell me that phosphorescent zucchini are safe! MegaCorp says they’re safe.” Stripped of the evidence, it becomes an example of a genetic fallacy. (Of course, the evidence about MegaCorp could be false, but with it the claim at least avoids the genetic fallacy.)

Now consider these claims: “Christianity was influenced by myths of dying-and-rising saviors; therefore, the resurrection of Jesus must also be a myth.” Or, “The Noah flood story came from a society influenced by neighboring flood stories like that of Gilgamesh; therefore, the Noah flood story is a myth.”

These are (1) genetic, since they make conclusions based on origins, (2) unsubstantiated, since these claims will need lots of supporting evidence, and (3) fallacies. I would argue that these aren’t genetic fallacies, however. They fail in my mind because the unequivocal conclusion (“… must also be a myth”) can’t be built on evidence that simply points in that direction.

The fallacy vanishes when we make a conclusion that could follow from the evidence: “Christianity was influenced by myths of dying-and-rising saviors; therefore, we must consider that the resurrection of Jesus may also be a myth.” We still have work to do to establish that Christianity was influenced as claimed, but the fallacy is gone.

The genetic fallacy is the term for any argument that points solely to origin as its evidence, but there are many subsets based on the specific origin.

  • Ad hominem: attacking the person rather than the argument. “Senator Jones wants to raise taxes, but he beats his dog; therefore, raising taxes is a bad idea.”
  • Tu quoque: saying, in effect, “Oh yeah? Well you do, too!” This argument tries to respond to a problem by claiming that the other person suffers from it also.
  • Argument from authority fallacy: using an authority as a relevant source when that person is not an authority in the field at hand, rejects the consensus view (if any), or is biased.
  • Credential fallacy: rejecting an authority because that person doesn’t have the right degrees.
  • Ad feminam: rejecting an authority because that person is a woman.

And so on.

Avoid making thoughtless charges of these fallacies. Not every attack on a person is an ad hominem fallacy. “Just ignore that fire alarm; that’s nutty Mrs. Smith” may be a fallacy, but “Ignore that fire alarm; that’s Mrs. Smith, and she’s phoned in a false alarm about every week for over three years” isn’t. (It may not be the safest response for the fire department, but it’s not a logical fallacy.)

And as seen above, not every genetic (origins) argument is a fallacy.

Photo credit: Simon Varwell

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Word of the Day: Argument from Authority (and How Consensus Fits In)

An authority could argue that God exists, but why believe them?I can’t count the number of times that I’ve said something like, “I accept evolution because it’s the scientific consensus” and gotten the response, “Gotcha! Argument from Authority Fallacy!”

Let’s take a look at this fallacy and see where it applies and where it doesn’t.

Suppose I said, “Dr. Jones is smarter than both of us put together and he agrees with me, so I’m right!” This statement could fail due to the Argument from Authority Fallacy for two reasons: (1) we haven’t established that Dr. Jones’ expertise is relevant to the question at hand, and (2) even if Dr. Jones is an expert on the subject, that he agrees with my position doesn’t make me right—at best, it would make me justified in holding my position.

Chastised at my poor argument, I go back and rework it. Now I’m careful to first establish Dr. Jones’ relevant expertise and I modified my claim this way: “Dr. Jones, an established authority, agrees with me, so therefore my position is well justified.” This is better, but my statement could still fail due to this Fallacy. What if Dr. Jones is a maverick in his field? He could be a cosmologist still holding on to the Steady State model of the universe now that the Big Bang model is the overwhelming consensus. Conversely, imagine that it’s the 1930s and he is arguing for an expanding universe when that was the minority position. Either position makes Dr. Jones a maverick, and the layman (as an outsider) has no grounds from which to conclude that this minority position is the best approximation.

The Argument from Authority is not a fallacy when the person indicated (1) is an expert in the field and (2) is arguing for the consensus. Of course, that doesn’t necessarily make you right, but being in line with the relevant consensus is the best that we can hope for.

I’m amazed when I hear people reject evolution who aren’t biologists. I can imagine browsing biology textbooks and concluding that evolution is a remarkable claim. I could even imagine thinking that the evidence isn’t there (though the fact that I’ve only dipped my toe into the water would scream out as the explanation for this). What I can’t imagine is concluding, based in my “research,” that the theory of evolution is flawed. I mean—on what grounds could I possibly make this statement? On what grounds could I reject the consensus of the people who actually understand this stuff? The people who actually have the doctorate degrees and who actually do the work on a daily basis?

And yet I hear people justifying this step all the time.

Let’s move on to another topic, the question of consensus. After many discussions that have forced me to carefully think my position, let me offer my views on consensus from different fields. Note that this is the view of a layman—someone who is an outsider to these fields.

  • Scientific consensus: I always accept this.
  • Historical consensus: I always accept this.
  • Consensus of religious scholars about their own religion: I always accept their statements of what their beliefs are. For example, when the consensus of Catholic scholars says that within the Catholic church the eucharist (the communion wafer) is believed to transubstantiate into the body of Christ, I accept that.

But don’t accept everything. I draw the line at supernatural claims, whether by scholars or believers, and whether the consensus or not. I will consider evidence for these claims, but so far I have always rejected them.  If I were to accept these claims, that would probably be based either the scientific or historical consensus.

Supernatural claims are in a very different category than scientific or historical claims.  For more, see my post Map of World Religions.

Photo credit: Wikimedia

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Word of the Day: Survival of the Fittest

What Would Jesus Say?The term “survival of the fittest” did not initially come from Charles Darwin’s Origin of Species, though later editions did use it. It was first coined by Herbert Spencer, after reading Origin.

While a convenient phrase, it can be confusing. “Fit” in biological terms doesn’t mean what we commonly think (strong, quick, or agile, for example) but refers to how well adapted an organism is for an environment. Think of it as puzzle-piece fit, not athlete fit.

Creationists sometimes use the phrase to mean that might makes right or that the most savage or ruthless or selfish will survive. On the contrary, rather than might makes right, cooperation can be the better approach. And even if evolution did have some bloodthirsty aspects to it, how does that change whether it’s an accurate theory or not?

NewScientist magazine says:

Although the phrase conjures up an image of a violent struggle for survival, in reality the word “fittest” seldom means the strongest or the most aggressive. On the contrary, it can mean anything from the best camouflaged or the most fecund to the cleverest or the most cooperative. Forget Rambo, think Einstein or Gandhi.

What we see in the wild is not every animal for itself. Cooperation is an incredibly successful survival strategy. Indeed it has been the basis of all the most dramatic steps in the history of life. Complex cells evolved from cooperating simple cells. Multicellular organisms are made up of cooperating complex cells. Superorganisms such as bee or ant colonies consist of cooperating individuals.

Note also that evolution is descriptive, not prescriptive; it simply says what is the case and doesn’t provide moral advice. “I’ll model my morality on evolution” makes as much sense as “I’ll model my morality on the fact that arsenic kills people.”

Creationists sometimes twist Darwin’s The Descent of Man to argue that he favored eugenics. Darwin’s damning paragraph said, in part, “hardly anyone is so ignorant as to allow his worst animals to breed.” In the first place, whether Darwin ate babies plain or with barbeque sauce says nothing about whether evolution is accurate or not. In the second place, the very next paragraph clarifies Darwin’s position about denying aid to the helpless.

Nor could we check our sympathy, even at the urging of hard reason, without deterioration in the noblest part of our nature.

“Survival of the fittest” is a handy description of natural selection as long as all parties understand what it means.

Photo credit: EvolveFish

Related links:

  • “Survival of the fittest,” Wikipedia.
  • Michael Le Page, “Evolution myths: ‘Survival of the fittest’ justifies ‘everyone for themselves,’” NewScientist, 4/16/08.

Word of the Day: Bronze Age Collapse

Can God and atheism coexist?The Trojan War of roughly 1200 BCE and the destruction of the city of Troy, about which Homer wrote the epic Iliad, was monumental enough in itself, but that period also marked the end of the Mycenaean Greek civilization. The Linear B writing system of the time was abandoned, never to be revived, and most of Greek cities of the time were destroyed or abandoned. Only after centuries of relative barbarism did the Greek city-states of Sparta, Corinth, Athens, and so on appear.

The Hittite empire in Anatolia (modern-day Turkey) also collapsed at the same time. So did the New Kingdom in Egypt.

Experts speculate on many possible causes of this Bronze Age Collapse—a meteor, drought, the eruption of an Icelandic volcano that caused climate change, the spread of iron weapons, and other causes. Certainly invasion was a factor, but does this explain everything or were these just opportunistic invasions after the existing empires were weakened? The cause(s) are still disputed and none explains all the facts.

Like a global extinction event that opens up niches for new species to invade, this collapse allowed new civilizations, technologies, and writing systems to emerge.

What happened to Israel, in the middle of these collapsing empires? The historical record is unclear—the traditional date for the Israelite conquest of Canaan had been about 1400 BCE, but the modern consensus is 1250. Perhaps the Bronze Age Collapse was a factor in jump-starting Jewish civilization. If nothing else, this setback for the nearby empires must’ve provided some breathing room for the people in the Levant.

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Word of the Day: Confirmation Bias

Christianity and atheism, does God exist?Sandy beaches often have a line of debris left by the last high tide. These lines look different on different beaches, reflections of the local environment. They might contain rocks, shells, seaweed, jellyfish, flotsam or garbage, egg cases from skate or conch, and so on.

When I was about 11, I spent a week at a beach on which amber occasionally washed up. After a little training, I got pretty good at seeing the amber. On a different beach, the prize was fossilized shark’s teeth, and again I got good at spotting them amid the pebbles.

Given a little training and motivation, the mind pulls out interesting things from the background chaos. What is the wheat and what is the chaff changes based on your needs.

Suppose you’re an emergency room nurse and comment on what a crazy night it’s been and a coworker says, “That’s always the way it is with a full moon.” Now that your mind has been primed, you may notice this coincidence often. But seeing this as more than just a coincidence without good evidence is confirmation bias. Confirmation bias becomes a problem when you sift through the evidence that you come across and select only those bits that confirm what you already believe. You don’t seek information but confirmation.

The hypothesis “God answers prayers” can also be supported by confirmation bias—those prayers that more or less come true within some broad time range are counted as successes, and those that don’t are either ignored or repositioned with, “Sometimes, God says no.” Psychics and horoscope watchers will similarly list successful predictions and ignore or forget the failures.

I listened to the weekly Reasons to Believe podcast from Creationist Hugh Ross for a while. It was little more than a selection of the few bits of evidence from the thousands of scientific articles that week that could be interpreted to support his old-earth Creationist views. Seeing this for what it is—an answer to the question, “What in this week’s news would support my Creationist preconceptions?”—would be fine. It’s when we imagine that this is objective science that we delude ourselves.

So that we evolution-accepting atheists don’t get too smug, Sam Harris proposed the Fireplace Delusion, a chance to have our own preconceptions challenged. It’s a good exercise by which to see your mind being offended and the defenses it puts up to maintain its initial position.

The mind is built to favor evidence that confirms an existing opinion over disconfirming evidence, and to combat this bias, science tries to disconfirm theories rather than confirm them. You can’t prove a scientific theory right, but you can prove it wrong. This reversal—testing our opinions with disconfirming challenges rather than selecting confirming evidence—is a good example to follow.

We can prime our mind, like we’re looking for shark’s teeth on the beach, to pull in only what we want to see, but we delude ourselves when we do so.

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Word of the Day: Theory and Law

A novel of Christian apologeticsLet’s start with a few definitions within mathematics and logic. An axiom or postulate is a proposition (statement) taken as a given. A lemma is an intermediate proposition or stepping stone rather than the final result, which is a theorem. A corollary follows readily from a theorem—it’s often simply another way of stating the theorem. Lemmas, theorems, and corollaries are all proven, but proofs are only possible within mathematics and logic, not within science.

By contrast, all scientific statements are provisional. A scientific hypothesis is a testable explanation for a phenomenon. It explains and predicts. Once a hypothesis has proven itself, it becomes a scientific theory. A scientific law is a description of a natural phenomenon, often an equation. Laws and theories are both well-tested, widely or universally accepted within the field, and falsifiable. The main difference is that a theory explains while a law describes.

For example, germ theory, quantum theory, and the theory of evolution are explanations. Boyle’s law, Ohm’s law, and Newton’s law of gravity are all descriptions (and are all equations).

A common misconception is that scientific hypotheses mature to theories, which mature to facts or laws. Instead, facts (the observations from an experiment, for example) lead to hypotheses (a plausible but immature explanation), which lead to theories (well-evidenced explanations). In the category of scientific explanations, a theory is as good as it gets and it doesn’t graduate to become a law.

Photo credit: Marvin (PA)

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