Wednesday, October 24, 2012

Inductive inferences across kinds

I observe some ravens, and they are all black. This gives me good reason to think all ravens are black. This is an inductive inference within a natural kind. One might have this picture of the inductive inference here: observing the ravens, we learn something about the appropriate-level universal raven that they fall under. One might then think that all inductive inference is like this: We observe instances of a genuine, non-gerrymandered natural kind K, and conclude that the kind is such-and-such.

But I don't think this is all that happens. Here are a few other kinds of cases.

  1. From the fact that octopi behave in some ways like we do, we infer that they are conscious. But there is no biological taxon K that contains both octopi and humans such that we have good reason to think that all Ks are conscious. The lowest level taxon containing octopi and humans is the subregnum Bilateria and we have little reason to think all Bilateria are conscious. We might seek for a natural kind that isn't a taxon, like critters that exhibit apparently intelligent behavior. But that's a gerrymandered kind. We might try for a non-gerrymandered kind, like critters that exhibit intelligent behavior, but then we would have to have reason to think that octopi exhibit intelligent behavior rather than merely apparently intelligent behavior, and our problem would return.
  2. We have good reason to think that all life on earth descends from a single ancestor. But organism on earth isn't a natural kind.
  3. We can do induction within artificial kinds. That all the pens that I have observed have ink in them gives me reason to think all pens have ink. But pen isn't a natural kind.

Does this matter? Maybe. (I think a theist may have a better explanation of why induction not-within-a-kind works than a naturalist. But the thoughts here are inchoate.)


Heath White said...

I would think, a priori, that induction would work well within natural kinds but I would not think, a priori, that induction would ONLY work well within natural kinds.

Dagmara Lizlovs said...

“I observe some ravens, and they are all black. This gives me good reason to think all ravens are black. This is an inductive inference within a natural kind. One might have this picture of the inductive inference here: observing the ravens, we learn something about the appropriate-level universal raven that they fall under. One might then think that all inductive inference is like this: We observe instances of a genuine, non-gerrymandered natural kind K, and conclude that the kind is such-and-such.”

There are some very unique and interesting exceptions to the above.

There are such things as white ravens. These ravens are not albinos, but leucystics. They are rare. They have been seen in different places like British Columbia and Alaska. Here are some interesting articles. And no, these birds of a different feather are not gerrymandered.

Then if we go to the exact opposite of us on the globe in Australia, the seasons are opposite ours, they drive on the opposite side of the road, their AM is our PM, we have white swans, they have black swans. These black swans are native to Australia and the surrounding region, and come under the genus “Cygnus” so they are true swans. They are not gerrymandered in any way.

Then there is the horse of a different color. Most of us think of Lipizzaner horses as grey/white or so it would seem from all the pictures from the famous Spanish Riding School in Vienna. Most members of this breed are born either brown or black and turn grey/white when they mature. Most, not all. A rare individual of this breed does not undergo this color change. I have always been intrigued by this variation in the Lipizzaner breed and I have seen one dark brown almost black stallion performing with the Spanish Riding School when they toured Philadelphia in 1990 or so. These rare black or brown Lipizzaners are believed by some to bring good luck. Here is one of the few black Lipizzaner stallions:

Now for the deer of a different color. There are rare varients in the coloration of white-tailed deer. Most white-tails are brown with a white underside. However there are some unique color variations.

The piebald white-tail. Occasionaly people come across them in my area.

The white non-albino white-tail deer. This deer is leucystic like the white raven.

Then there is the very rare melanistic white-tail deer.

None of these animals are gerrymandered in anyway.

Then not all skunks are black with white stripes. Some are all white, and some are cream/champagne colored. I like the cream colored ones best.

Vive la difference!

March Hare said...

Strikes me you've failed to describe what a 'natural kind' is and so I'm left with the idiotic ID explanation which is "anything that is sufficiently same/different to advance whatever argument against evolution I am making at this time."

Similarly, just because bats and birds both exhibit behaviours that suggest flight but lack a 'biological taxon K that contains both bats and birds' should we doubt that that bats and birds can fly?

Or, can we simply conclude that certain abilities can evolve separately in different lineages over time?

Kenny Pearce said...

Modern biology identifies taxa by common ancestry. This does indeed create a problem for those people who go around saying they only believe in 'micro-evolution' i.e. evolution within a genus, because they have no non-circular way of saying what a genus is. (According to their view, the genera are the largest collections of animals with common ancestors, but they can't use this definition, because then the mainstream evolutionists will just say that in that non-standard sense of 'genus' there is indeed a genus that contains all organisms on earth.) It doesn't, however, create a problem for this argument. After all, one cannot reason '(most) birds can fly, so probably bats can fly' in the way one can reason '(most) birds can fly so probably canaries can fly.' One can observe both birds and bats flying and so know that they can both fly, but that's not induction. One could also look at their wings and know from physics that either set of wings could possibly be used to fly. Perhaps, however, birds and bats are indeed the sort of case we are looking for, if 'winged animal' does not name a natural kind (and it presumably doesn't). For perhaps it would be reasonable, observing the similarities between bat wings and bird wings to conclude even without knowledge of physics that the latter, like the former, must be for flying. If so, then this would be induction outside natural kind boundaries. (I worry, though, not only about using background physics knowledge, but also about some kind of teleological reasoning: this body part must have some kind of use, the only use we can come up with for it is flying, so it's probably for flying.)

Now, first, the whole line of thought presupposes that there is some kind of metaphysical significance to biological taxa, but that claim is accepted by many philosophers. Second, it requires that there not be too many more natural kinds besides the taxa. It seems to me to require not only that 'winged animal' not name a natural kind of animal, but also that 'wing' not name a natural kind of body part, otherwise we could say '(nearly) all observed wings have been used for flying, so probably these wings are used for flying.'

Alexander R Pruss said...

March Hare:

I am not advancing any argument against evolution here or against the possibility of convergent evolution. It's just that convergent evolution causes problems for one kind of story about how induction works.


While there is a significant movement to identify all taxa by common ancestry, this isn't universally accepted. I expect a lot of biologists still talk of reptiles, even though any common-ancestry-defined taxon that includes reptiles also includes mammals and birds.

Moreover, species are defined by significant genetic interchange within a group rather than by common ancestry.

I like the wing example.

I wonder, though, whether one couldn't say that although 'winged animal' doesn't name a natural kind, 'wing' does. If so, then one can do induction within the natural kind wing and conclude that wings are for the most part (flightless birds...) had by flying animals.

Dagmara Lizlovs said...

I would like to reiterate the Catholic Church's position on evolution. The Catholic Church does not oppose evolution per se. What the Church does oppose is the position that the universe and humanity evolved from blind chance without a Creator. I will take some excerpts from “The Genesis Controversy” by George Sim Johnston. Full article found here:

“St. Augustine set forth in his commentaries on Genesis – that in the beginning God created all living things not immediately, but “potentially in their causes.” God, according to Augustine, placed in his creation seeds (rationes seminales ) which remained “in the hidden recesses of nature.” Augustine understood evolution in the strict etymological sense of the word – an 'unfolding' of what is already there. . . In De Genesi ad litteram he asserts that the account of creation could not possibly have been meant to be taken literally. And since Augustine, the Church has never subscribed to a literal reading of the first chapters of Genesis. Catholic thinkers have generally deemed the account of creation as theologically true, if not strictly factual – a poetic compression of the truth, as it were. Darwin's theory was never the bombshell for Catholics that it was for Protestants adhering to a literal reading of scripture. Darwin himself said that as a young man he had believed the 'strict and literal truth of every word in the Bible' and lost his faith when it became clear that 'science' disproved Genesis. He was not the last Protestant to do so. . . In his 1950 encyclical Humani Generis, Pius XII, while pointing out correctly that the theory of evolution 'has not been fully proved', permitted ‘research and as far as it requires into the origin of the human body as coming from pre-existent matter.’ But whatever the findings of science, Pius affirmed, Catholics must believe that ‘God intended, from all eternity, to create...and he took those means which he saw to be the most suitable to the purpose.’”

I will take another excerpt from another article “The Pope and the Apes” by George Sim Johnston. Full article found here:

“So the pope (John Paul II) objects to philosophical materialism masquerading as science, which is what we find in books by Darwinists. Pop scientists like Richard Dawkins and Carl Sagan start with a philosophical premise: There is no God. This allows them to embrace a teleological taboo that makes Darwin a winner by default. But their explanation of how the bacteria that appeared billions of years ago produced the incredible diversity of life we see today relies more on hidden postulates than empirical evidence. Darwinism in their hands really amounts to a countermetaphysics planted like a foreign body in the heart of biology. . . Evolution actually has an ancient Catholic pedigree. St. Augustine was an evolutionist, although hardly a Darwinist. In his second commentary on Genesis, he surmised that God had planted “rational seeds” in nature that had fructified in due course. This is evolution in the strict etymological sense of the word, an unfolding of what is already there, like an acorn turning into an oak. . . It makes no difference whether man is descended biologically from some ape-like creature, so long as we understand that there had to be what the pope calls an “ontological leap” to the first human person. This would have involved the direct action of God, who creates each rational soul out of nothing.”

Dagmara Lizlovs said...

More on white ravens and black ravens. This is a bit of topic, but since this post started off with black ravens and I showed that there were white ones too, here is one of many Native American stories on how the white raven came to be black:

March Hare said...

"It's just that convergent evolution causes problems for one kind of story about how induction works."

Not really. It poses problems for trying to do induction with insufficient data. If we look closer at bats and birds we start to see striking differences and also some similarities that allow us to do much better predictions in future.