“‘Teleology is like a mistress to a biologist: he cannot live without her but he’s unwilling to be seen with her in public.’ Today the mistress has become a lawfully wedded wife. Biologists no longer feel obligated to apologize for their use of teleological language; they flaunt it.
Sure, so long as you recognize that “purpose” in
“The purpose of the heart is to pump blood.”
cashes out as something different from
“The purpose of the silicon CPU is to implement a truth table.”
In my experience, there are about zero philosophers of science who both understand this distinction, and harp on this point about teleology in biology. Here is one I read recently.
In one case, we have a mind to attribute purpose to—and in the other we don’t.
However, both are complex adapted systems, produced by other, larger complex adapted systems as part of an optimisation process. If that is all we mean by “purpose”, these would be classified in much the same way.
I didn’t like the “No Teleology!” link much—it seemed pointless.
I use the term “cashes out” because that’s the lingo here. But I’ll expand out the two claims to show how they’re different in a crucial way.
In the case of the heart’s purpose, the statement means, “Historically, genes were copied to the next generation in proportion to the extent to which they enhanced the capability/tendency of organisms whose DNA had that gene to make another organism with that gene. At an organism’s present state, a gene complex causes a heart to exist, which causes blood to increase in pressure at one point in its circulation, which causes the organism to stay away from equilibrium with its environment, which permits it to pass on the genes related to the heart (the latter being the critical explanatory feature of organism). If the heart ceased causing the blood to increase in pressure, the organism would lose its ability to remain far from equilibrium (which as mentioned above relates to an aspect with critical explanatory power) much faster and securely than if the heart ceased causing any of its other effects, such as generation of heat.”
In the case of the CPU’s purpose, the statement means, “The CPU was added to the computer system because a human designer identified that fast implementation of a truth table would be required for the computer system to do what the human designer intended (which is fast input/output of computations related to what human users will want out of it), and they recognized that inclusion of the CPU would lead to fast implementation of a truth table.”
Quite a mouthful in each case! So it’s quite understandable when the distinctions are glossed over in simplified explanations of the topics.
But the important thing to notice that if you take the meaning of “purpose” in the biological context to mean something more like it does in the computer context, you are led into critical errors. For example, you will have a hard time recognizing evolutionary paths, particularly when organs are—for lack of a better term—“repurposed” (or “exapted” in the lingo) to do something in a later generation, that they didn’t do—or which wasn’t as critical—in an earlier generation. (Or in a comtemporary homologue.)
After all, if “the” purpose of feathers is to keep warm in one generation, how can “the” purpose of those features be to fly in another? If “the” purpose of a limb is to swim in one generation, how can it be to walk in another?
I didn’t like the “No Teleology!” link much—it seemed pointless.
Why? Gene Callahan seems to be arguing the same thing you are about biology. At the end of the exchange, bestquest describes the sense in which “the function of the heart is to pump blood”, and then Callahan erroneously dismisses that phrasing as being teleological.
Sure, so long as you recognize that “purpose” in
“The purpose of the heart is to pump blood.”
cashes out as something different from
“The purpose of the silicon CPU is to implement a truth table.”
In my experience, there are about zero philosophers of science who both understand this distinction, and harp on this point about teleology in biology. Here is one I read recently.
“Cashes out” seems rather vague.
In one case, we have a mind to attribute purpose to—and in the other we don’t.
However, both are complex adapted systems, produced by other, larger complex adapted systems as part of an optimisation process. If that is all we mean by “purpose”, these would be classified in much the same way.
I didn’t like the “No Teleology!” link much—it seemed pointless.
I use the term “cashes out” because that’s the lingo here. But I’ll expand out the two claims to show how they’re different in a crucial way.
In the case of the heart’s purpose, the statement means, “Historically, genes were copied to the next generation in proportion to the extent to which they enhanced the capability/tendency of organisms whose DNA had that gene to make another organism with that gene. At an organism’s present state, a gene complex causes a heart to exist, which causes blood to increase in pressure at one point in its circulation, which causes the organism to stay away from equilibrium with its environment, which permits it to pass on the genes related to the heart (the latter being the critical explanatory feature of organism). If the heart ceased causing the blood to increase in pressure, the organism would lose its ability to remain far from equilibrium (which as mentioned above relates to an aspect with critical explanatory power) much faster and securely than if the heart ceased causing any of its other effects, such as generation of heat.”
In the case of the CPU’s purpose, the statement means, “The CPU was added to the computer system because a human designer identified that fast implementation of a truth table would be required for the computer system to do what the human designer intended (which is fast input/output of computations related to what human users will want out of it), and they recognized that inclusion of the CPU would lead to fast implementation of a truth table.”
Quite a mouthful in each case! So it’s quite understandable when the distinctions are glossed over in simplified explanations of the topics.
But the important thing to notice that if you take the meaning of “purpose” in the biological context to mean something more like it does in the computer context, you are led into critical errors. For example, you will have a hard time recognizing evolutionary paths, particularly when organs are—for lack of a better term—“repurposed” (or “exapted” in the lingo) to do something in a later generation, that they didn’t do—or which wasn’t as critical—in an earlier generation. (Or in a comtemporary homologue.)
After all, if “the” purpose of feathers is to keep warm in one generation, how can “the” purpose of those features be to fly in another? If “the” purpose of a limb is to swim in one generation, how can it be to walk in another?
Why? Gene Callahan seems to be arguing the same thing you are about biology. At the end of the exchange, bestquest describes the sense in which “the function of the heart is to pump blood”, and then Callahan erroneously dismisses that phrasing as being teleological.