The wasp that devours the caterpillar
The argument from bad design (or from imperfection)
The details of living things were not willed piece by piece by a good and all-powerful God, and they give no reason to believe so: nothing obliges us to think that the eye was expressly designed. The question of God remains open: Darwin leans towards designed laws, "with the details, whether good or bad, left" to what we may call chance, and judges the subject "too profound for the human intellect".
A good God willing every detail would not have made the cruelty found in living things, which natural selection does predict.
"The wasp that devours the caterpillar" is an argument by Charles Darwin (Letter to Asa Gray, 22 May 1860; On the Origin of Species (1859), 1860) on the question "Does God exist?" (answer: agnosticism). Its claim: The details of living things were not willed piece by piece by a good and all-powerful God, and they give no reason to believe so: nothing obliges us to think that the eye was expressly designed. The question of God remains open: Darwin leans towards designed laws, "with the details, whether good or bad, left" to what we may call chance, and judges the subject "too profound for the human intellect". According to AskPhilosophy's logic check (Z3 solver), the argument is valid only if one grants a premise the author leaves unstated (P4). AskPhilosophy presents 5 objections, 2 of them with a documented reply, and the original text behind each premise, checked word for word.
Paley said: look at the eye, it was designed. Darwin answers: look at the rest too. Some wasps, the ichneumons, lay their eggs in living caterpillars, which the larvae devour from the inside. The bee dies of its own sting. Animals carry organs that are of no use. Would an all-powerful and good engineer have done this on purpose? Natural selection, by contrast, predicts these flaws. Darwin does not conclude that there is no God: he writes that he "had no intention to write atheistically" and later calls himself an agnostic. Classification: the argument takes away the evidential value of nature's details without settling the question of God; that is why we file it, as Darwin himself would, under agnosticism. Gould and Dawkins later use it in favour of atheism.
click a premise to reject it
Without the implicit premise: Without P4, the computer finds a case where the flaws exist, where selection predicts them, and where there would still be good reason to believe in detailed design: so one has to say that facts better predicted by another explanation do not count in favour of this one.
Objections
5Each objection is a conversation: click to see who replies and where the debate stands.
William Paley 1802 · attacks premise 1A machine does not need to be perfect to show that it was made for a purpose. A watch that runs slow is still a manufactured watch. Flaws raise a question about the craftsman's skill, not about his existence; and they may come from the intractability of the materials or from a difficulty of execution that we do not see.
no reply
A machine does not need to be perfect to show that it was made for a purpose. A watch that runs slow is still a manufactured watch. Flaws raise a question about the craftsman's skill, not about his existence; and they may come from the intractability of the materials or from a difficulty of execution that we do not see.
William Paley 1802 · attacks premise 1The viper's fangs, the wasp's sting, the claws of predators were indeed intended. The only question is whether, in the end, this is an evil. Our knowledge is limited: there may be hidden consequences that would tip the balance to the good side. And for a wild animal, being killed quickly by a predator may be better than dying slowly of hunger and old age.
Darwin replies
The viper's fangs, the wasp's sting, the claws of predators were indeed intended. The only question is whether, in the end, this is an evil. Our knowledge is limited: there may be hidden consequences that would tip the balance to the good side. And for a wild animal, being killed quickly by a predator may be better than dying slowly of hunger and old age.
AAsa Gray 1860 · attacks the conclusionThe American botanist, Darwin's friend and a Christian, accepts selection. But as long as the cause of variation remains unknown, one may suppose that it has been led along beneficial lines, like streams that carve their own beds yet whose course was intended. Selection would be design's tool, not its replacement.
Darwin replies
The American botanist, Darwin's friend and a Christian, accepts selection. But as long as the cause of variation remains unknown, one may suppose that it has been led along beneficial lines, like streams that carve their own beds yet whose course was intended. Selection would be design's tool, not its replacement.
MMichael Behe 1996 · attacks premise 1The argument from imperfection demands perfection at every level and assumes we know what a designer meant to do. Yet a designer's reasons are virtually impossible to know unless the designer tells us. An imperfect or makeshift object may well have been designed: our cars and computers are not perfect.
no reply
The argument from imperfection demands perfection at every level and assumes we know what a designer meant to do. Yet a designer's reasons are virtually impossible to know unless the designer tells us. An imperfect or makeshift object may well have been designed: our cars and computers are not perfect.
Alvin Plantinga 1974 · attacks premise 1It is possible that natural evil is due to free nonhuman beings. According to traditional doctrine, Satan, a mighty spirit created before man, rebelled against God and has since been wreaking whatever havoc he can. If this is possible, evil in nature is not inconsistent with a good and all-powerful God.
no reply
It is possible that natural evil is due to free nonhuman beings. According to traditional doctrine, Satan, a mighty spirit created before man, rebelled against God and has since been wreaking whatever havoc he can. If this is possible, evil in nature is not inconsistent with a good and all-powerful God.