One of the many public controversies about science swirling around nowadays concerns so-called GMOs, or Genetically Modified Organisms. It has become fashionable in certain quarters to bash any criticism of GMOs, regardless of whether it is directed to their alleged health implications, to their (again, alleged) long-term environmental impact, or to the (much less alleged and more concrete) market and labor practice of large GMOs producers like Monsanto.

To make my stance perfectly clear from the outset and not sidetrack the discussion, here is what I think at the moment, given the evidence so far, my readings of (part of the huge) literature, and my own biases and preconceptions:

i) I do not think there is any reason to be concerned about adverse health effects of GMOs that are currently on the market, or that will be produced using similar methods and certification protocols.

ii) I do not think there is currently a good reason to be worried about long-term adverse environmental impact of GMOs, although here the issue is more complex, at the very least because any form of large-scale agriculture based on mass production of a small number of edible species should be of concern.

iii) I do think that GMOs producers have been engaging in questionable to highly questionable market and labor practices, and that they ought to be strictly regulated, as should the food industry in general — but then again I’m known to be a social-democrat with Chomskyan tendencies, so there.

Needless to say, all three of these positions are open to revision, in one direction or the other, should new pertinent evidence come out to change my priors.

So what’s this essay about, then? It concerns my objection to the use of bad arguments even when one is right, and “skeptics” of a pro-science persuasion all too often engage in just that questionable practice. For instance, in my Nonsense on Stilts: How to Tell Science from Bunk I noted that some critics of ufology have not hesitated to simply make up out of whole cloth “explanations” for some sightings of alleged flying saucers. Turns out there was — of course — natural and mundane explanations for those sightings, but the true skeptics had not bothered to look for them, cocksure as they were that UFOs don’t exist (they don’t, really).

This is a point that was made decades ago by one of my least favored philosophers of science, Paul Feyerabend, when he provocatively went around defending astrologers and creationists to make the point that the scientific establishment was not carrying out its epistemic duty to inquire rather than dismiss.

Back to GMOs. The attitude that I criticized in those skeptics of UFOs re-appareaded in a blog post by one “Skeptical Raptor,” of whom I know nothing except what s/he writes about him/herself: “Lifetime lover of science, especially biomedical research. Spent years in academics, business development, research, and traveling the world shilling for Big Pharma.”

Raptor wrote a post entitled “Ten thousand years of GMO foods — making inedible edible,” an article which was immediately reposted by my own favorite skeptic organization, New York City Skeptics, and which repeats claims I’ve heard made with confidence by highly prominent skeptics, such as Michael Shermer of Skeptic magazine.

Here is the claim, in Raptor’s very own words: “One of the tropes of the anti-GMO movement is that nature does it better for food, a logical fallacy. In other words, they believe that our ancestors’ foods are somehow better than our GMO foods. Of course, this belies the fact that there are over ten thousand years of GMO foods – it’s really not something that showed up during the last century or so.”

Ah, the old trick of scoring a quick victory by accusing one’s opponents of committing a logical fallacy, in this case the “appeal to nature” one. (Never mind that my colleagues Maarten Boudry, Fabio Paglieri, and I have shown that far too often alleged fallacies are actually pretty good heuristics, and that it isn’t very helpful to simply label another’s argument as fallacious without explaining in some detail why exactly that is the case in each specific instance.)

Raptor first makes an irrelevant swipe at creationists (I wonder, was that a red herring type fallacy?) and then rhetorically asks: “what is the difference between the genetic manipulation of our ancestors, who had to wait for the right mutation, or modern biotechnology, which finds the best mutation and places it in the plant? Not really that much, unless, and I can’t stress this enough, you think that ‘nature’ has some supernatural power.”

No, this has nothing to do with Nature’s supernatural powers, but it does have to do with the fact that artificial selection is not at all the same process as the production of GMOs in the modern sense of the term. They are very different things, and to pretend that the second is simply a continuation of the former is bad for critical thinking, and ultimately undermines one’s own (otherwise perfectly reasonable) argument.

As it turns out, there are two categories of GMOs: the first is the result of genetic engineering that uses as source material DNA from the same species, the second one is obtained by engineering a novel genome by importing DNA from a different species. The technical term for the second class is transgenic organism. Much of the fracas about GMOs has to do with transgenics (otherwise tendentiously known as “Frankenfoods”), not with GMOs obtained by modification of their own species’ genetic makeup.

Now, from a scientific perspective there are at least five different ways of producing genetically novel crops:

I) old fashioned artificial selection relying on naturally occurring genetic variation (which we have been doing since at the least the agricultural revolution);

II) cross-breeding of different but genetically compatible species, as in the case of commercial orchids, for instance;

III) enhanced artificial selection, where the selection is preceded by a treatment that greatly increases the natural, standing genetic variation — for instance by exposing the organisms to radiation that causes a much larger number of mutations than normal;

IV) intraspecific GMOs;

V) transgenic organisms.

It makes no sense, from a biological standpoint, to claim that these are all the same thing, and much less so to claim that (V) is no different from (I), which is where all the controversy is. Selecting random variations that are already present in a population of organisms is e qualitatively completely distinct process from extracting the DNA from one species, inserting it into a suitable “vehicle” (usually a virus, though we now have other methods, including gene guns), and then using that vehicle to incorporate the foreign DNA into a different species. In fact, pretty much the only thing the two processes have in common is the word “DNA.”

Now, Raptor and the other skeptics are correct when they say that there is no evidence of (V) being any more dangerous to our health than (I) (or II, or III, or IV, for that matter). But it just isn’t right to claim that they are the same thing that we’ve been doing for thousands of years. They aren’t, and we haven’t.

This is not a matter of being pedantic about science minutiae. Truth and honesty are important values that are all too frequently ignored or trampled in contemporary public discourse. We don’t need to help ourselves to false or inaccurate claims to make our case, because the facts (so far) make it for us. Let’s stick to the facts, then, shall we?

MASSIMO PIGLIUCCI IS THE K.D. IRANI PROFESSOR OF PHILOSOPHY AT THE CITY COLLEGE OF NEW YORK. HIS BACKGROUND IS IN EVOLUTIONARY BIOLOGY AND THE PHILOSOPHY OF SCIENCE, THOUGH HE HAS RECENTLY DEVELOPED A KEEN INTEREST IN STOICISM. HIS MOST RECENT BOOK (CO-EDITED WITH MAARTEN BOUDRY) IS “PHILOSOPHY OF PSEUDOSCIENCE: RECONSIDERING THE DEMARCATION PROBLEM” (UNIVERSITY OF CHICAGO PRESS, 2013). HIS OTHER WRITINGS CAN BE FOUND AT PLATO’S FOOTNOTE.