Yesterday, I posted some thoughts on "Forks Over Knives," an excellent new documentary film that discusses the extreme damage that humans inflict on themselves by eating animal products. The film summarizes the work of Drs. T. Colin Campbell and Caldwell Esselstyn, each of whom independently found that people who eat plant-based foods are healthier than people who eat animals and their secretions. The differences in health outcomes are, moreover, extreme, with societies that exploit animals suffering from deadly diseases that are virtually unknown to societies that eat plants.
[Note: Toward the end of yesterday's post, I asserted that the film had engaged in product placement for a high-end grocery store chain. The creator of the film posted a polite reply on the comment board, stating that what I took to be paid-for in-movie advertising was no such thing. I have posted an apology and clarification at the beginning of yesterday's post.]
One of the best aspects of the film is the director's even-handed treatment of those who disagree with his conclusions. As I mentioned in yesterday's post, he uses interviews with a professional nutritionist to display the existence of gross ignorance even among those whose job it is to know the effects of diet on health. Unlike all too many documentarians, however, he does so without making the interviewee look ridiculous. He allows her simply to say the wrong-headed things that she says, but he refrains from snarky comments, unfair editing or framing, or other tricks of lesser documentarians. Even so, the audience is presented with sufficient information that there is never any doubt that the interviewee is grossly misinformed.
At one point, the film investigates the government's role in promoting bad health choices. Unsurprisingly, the meat and dairy industries have inordinate influence over what the federal government says and does about people's dietary habits. The U.S. Department of Agriculture is, sad to say, essentially a marketing arm for those who torture and kill animals, playing down the conclusions of scientific research that would suggest that people should not eat animals or their secretions. USDA research is largely performed by scientists who have made enormous sums of money from contracts with the beef, pork, poultry, and dairy industries. This conflict of interest makes it rather easy to suspect that the government's pronouncements on healthy eating cannot be trusted.
The government's response to this conflict of interest was fascinating. The filmmaker interviews the top man in USDA on such matters, who offers a two-pronged response to the suspicious connection between industry money and government-sponsored scientific research: (1) It is only natural that both government and business would want to hire the top people in the field to conduct research, so there is nothing surprising about seeing those brilliant scientists' names both on government studies and on industry paychecks, and (2) In addition to financial conflicts of interest, there are also personal conflicts of interest, and Drs. Campbell and Esselstyn are biased by their extreme commitment to the cause of plant-based diets.
The defense of the current incestuous relationship between industry and government research, therefore, boils down to this: "Government cannot find anyone qualified who is not financially conflicted, and besides, these veggie guys are loonies." It is a brilliant riposte, simultaneously burnishing the qualifications of the government's scientists, and denigrating their opponents.
There are two types of ad hominem attacks. First, there is the "circumstantial" attack, which says that an argument should not be believed because the person making the argument has reason not to be honest. "Don't believe the defendant, because he is naturally going to lie to save his skin," and "Car salesmen aren't trustworthy" are both examples of this kind of attack. Second, there is the "abusive" attack, which says that an argument should not be believed because the person making the argument is personally repellent in some way. "That's what I'd expect to hear from an ignorant buffoon," and "Why do you hate America?" are in this category.
Such attacks are fallacious in that they do not go to the truth or falsity of the argument. Even so, it is obviously not enough to dismiss the USDA official's arguments merely because he relies on ad hominem attacks -- "Our guys are smart, and your guys are nuts." The attack on the government's researchers is itself clearly also ad hominem, as are all concerns about conflicts of interest. We can make a bit of progress by noting that the USDA's arguments tend toward the abusive rather than circumstantial end of the scale, but that is still not enough to do justice to the issues raised.
The first point, that all the top scientists would naturally already be on industry's payroll, is really quite startling in its implications. It simply assumes that there is not (and probably should not be) any expectation that scientists should maintain their independence, in order to be able to engage in uncompromised empirical inquiry. Apparently, all of the recent concern over industry-financed medical research is much ado about nothing. Why, after all, should we not expect smart guys and gals to sell themselves to industry for the big paycheck? They are the best scientists, by definition, because industry went after them with a lot of money. And they accepted, as any sensible person would do.
We hope, of course, that people will be able to maintain their independence, even if future riches are dependent on giving their paymasters the answers that they want. We would also hope that scientists would be able to avoid the tendency to internalize what everyone around them is saying. If, on a regular basis, we saw examples of industry-financed studies that ran counter to an industry's interests, we might have some reason to think that there is nothing to worry about. It is possible, however unlikely, that we do not see such examples because the unbiased scientific answer is always on the side of industry. Or, the scientists might simply be producing unbiased research, but only the industry-friendly work is being published. If that is happening, however, then we would need an explanation as to why independent scientists would not fight to publish the truth -- or, at least, why they would sign subsequent contracts to produce industry-sponsored research.
The attack on Drs. Campbell and Esselstyn, on the other hand, can plausibly be characterized as less an abusive attack ("They're crazy sprout-lovers") than the statement that they have honestly become obsessed with an idee fixe. They might be smart guys, but at some point they went off the rails and became evangelists rather than independent scientists. If this were true, they would deserve our pity and indulgence, but not our respect. Certainly, their scientific claims would have to be rejected.
Surprisingly, therefore, the USDA representative's ad hominem comments (about the government's scientists, and Campbell and Esselstyn) are not pure hogwash. We would be crazy not to take circumstances into account when assessing the validity of scientists' claims, which is exactly what we are doing when we express skepticism about industry-funded research in the first place. We would also be wise to consider the possibility that some people simply become obsessed with their own agendas.
Even so, it seems rather clear that we should be able to expect that industry should not be able simply to buy all the "best" scientists. Moreover, there is a way to determine whether Campbell and Esselstyn are distorting the truth. Even though ad hominem considerations cannot be completely ignored, after all, they are only indirect suggestions about the underlying truth of the matter. As "Forks Over Knives" shows, Campbell and Esselstyn have engaged in rigorous scientific research, based on extensive data collection, and found that both individuals and societies are severely harmed by animal-based diets. No amount of touting the government scientists' credentials, or dismissing Campbell and Esselstyn as cranks, changes those facts.