Friday, May 4, 2012

Should we be concerned about plants?

A recent essay in the New York Times (If Peas Can Talk, Should We Eat Them? by Michael Marder) about the "ethical implications" stemming from research on pea plant "intelligence" prompted me to finish writing this post. This isn't really a new story, as the essay points out, as speculation of this kind has been going on since at least the 1970s. I started the post after an online exchange with someone about virtually the same topic. Not coincidentally, they're both philosophers.

The NYT essay details some recent findings about how plants communicate. The research was done on pea plants and as with most plant communication, involves sending out biochemical signals which other plants respond to. Again, this is not particularly new but as a biologist I am impressed with the complexity of interactions between plants. Indeed, I'm happy go on record conceding that plants are wonderfully complex organisms that are capable of rudimentary communication, biochemical memory etc. - for a review see this. However, it's mystifying to me that anyone who has taken high school biology and can think clearly would believe this raises any kind of ethical issue.
In the first place, we don't kill pea plants to eat them (even though there are some plants that we do consume this way). We cultivate pea plants and then harvest the peas. Peas are how pea plants reproduce - the plants live only one growing season, produce seeds and then die. The seeds are dispersed in the evolutionary hope that some of them will find a suitable location to sprout the following year and complete the cycle. When humans intervene in this process by gathering peas in the summer and then planting a portion of them the following spring we are doing the plants a favor. Their existence as plants is unaltered by our intervention except for the better. We protect them, fertilize them, water them and distribute their seeds widely. I'm not a philosopher, but I don't see any "ethical implications" here.
As it turns out, the vast majority of plant foods that humans eat fall into this or a very similar category. Fruits and vegetables are similarly produced by plants so that animals will be attracted to them and in the process of consuming them will disperse the seeds they contain. All grains, legumes, nuts, fruits and most vegetables that are consumed by people are produced by plants for the purposes of reproduction and don't involve killing the plants. So far, as a vegan, my conscience is pretty clear. Meanwhile, the author of the NYT essay is waxing poetic about how serious this all is - "Inquiring into justifications for consuming vegetal beings thus reconceived, we reach one of the final frontiers of dietary ethics." Seriously? Is this the best contemporary philosophy has to offer? Thankfully it isn't as Peter Singer's work demonstrates.
Secondly, even when we consume plants, such as lettuce or other leafy greens, where the whole plant is eaten there is absolutely no indication that plants suffer or feel pain by any reasonable stretch of the imagination. Animals, on the other hand, can show very clear indications of feeling pain and suffering while being raised and killed as "food animals" by humans. At least this is what I thought... During an exchange with someone on Facebook I learned how drastically "contemporary philosophy" and some fuzzy thinking can be used to turn these fairly simple observations around.
It started with one of the many vegetarian/vegan posts that are put up on Facebook (at least when you are friends with as many vegetarian/vegans as I am). I will try to paraphrase the other fellow's stance but it's somewhat difficult as he seemed mainly intent on challenging other peoples' assumptions and justifications rather than clearly setting out his own. He cited similar research on plants to that reported in the NYT essay and indicated that if we were to observe plants using time lapse photography they might seem more animal like in their responses. This seemed to be the basis for a belief that "Life is life" and "If it's wrong to eat a cow, how about an insect? If it's wrong to eat an insect, then how about a piece of fruit?" Really?
It seemed that none of the arguments I made that might differentiate a cow from a lettuce plant were valid. Who knew that the fact that we are so much more closely related evolutionarily to cows than lettuce plants and that humans and cows have such similar nervous systems and physiologies is no basis to believe that they feel pain and suffer like we do? The observation that cows seem to react in a similar way to the same kinds of stimuli that humans would react to is also a completely invalid argument. All those millions of years of evolution developing our "theory of mind" was completely worthless by this line of thinking. Frankly, as a scientist I was a little taken aback by the arrogance of his comments, as if philosophers were the only people who could think clearly about anything. Scientists use methods all the time that are known to potentially give misleading conclusions - statistics comes to mind. We know what the potential flaws are and use other methods to make sure we are not being led astray. The alternative is to throw up your hands and say that we can never know anything, hummmm......
I guess if someone could produce a time lapse video of a lettuce plant "running" away from an approaching hungry vegan I might be a little more convinced (how would a lettuce plant run anyway?). Yet, if we had such a video why would this indicate that plants are experiencing fear when very clear evidence of animals doing this is insufficient for philosophers to accept that animals experience the same emotions as we do? Why the acceptance of potential plant sensitivity and the utter rejection of animal sensitivity? Once again, if this is an example of what contemporary philosophy has to offer, I am not impressed!
Indeed, you might think that people who seem to be so sensitive to the subtle reactions of plants would be constructing a diet that would minimize this kind of trauma - perhaps only eating fruits and seeds, but you'd be wrong. These "concerns" about plants seem to be mainly an attempt to create a false equivalence between plants and animals regarding ethical considerations. But rather than this leading to more ethical eating it seems to lead to a complete abdication of any ethical concerns when it comes to eating - after a long hard day of philosophical consideration of these matters they are free to eat whatever they want. "Yes waiter, I'd like the veal cutlets and some foie gras as an appetizer..."
Even if you believe that plants are capable of all the kinds of responses that animals display this is no justification to eat animals. As I have demonstrated above, most plant foods don't involve killing plants or even disrupting their life cycle (if you are really that concerned) and producing them certainly doesn't involve the kind of pain, suffering and early death that "food" animals endure. I don't know the motives of these people but the fact that these kinds of arguments lead to abandoning ethical behavior when it comes to diet rather than informing it gives me some clue.
However, even though I'm a life-long vegetarian and decades-long vegan I don't believe that my diet is free of any ethical issues. I know about the animals that are killed in industrial monoculture farming - it's still better to eat the corn than feed a whole bunch of it to animals and then eat the animals. I know that people work many backbreaking hours to pick fruits and vegetables so I try to purchase more local and organic foods but I know what I do is not perfect. I feel very lucky that I live at a time that allows me to mainly avoid animal cruelty for my daily sustenance. Further, I don't consider myself morally superior to people around me that choose to eat differently than I do. People make food choices every day and even though I know I can do better I am comfortable with mine. What I'm not concerned about, however, are any "ethical implications" involving eating plant foods - you shouldn't be either.