Ants and robots, parlour games and steam drills 5
Competing with the steam drill in an epic battle at the height of the industrial age,
our folk ballad’s hero scored the costliest of victories. Exhausted from his successful race against the machine, John Henry was found “dying with his hammer
in his hand”. In this tragic manner, he has become an African American folk hero,
as a symbol of black workers’ struggle for respect in a society where many odds
were against them. One of these odds was the progressive displacement of their
labour by machines.
In keeping with Turing Machine functionalism, the previously quoted passage
suggests that such displacement normally works precisely because machines do
not reproduce or replicate human organic features and behavioural patterns, but
because they achieve the results of goal-directed human behaviours more quickly,
more effectively and more efficiently – or because they enable the achievement
of certain, hitherto unattainable, goals in the first place. The steam drill outlasted
John Henry not because it was like him, only stronger, more enduring, but because
it was very much unlike him. Hence, analogy in function does not require similarity in structure. Provided that the task in question is well-defined, any structure
that produces effects that result in the accomplishment of that task, and that produces these effects in accordance with an equally well-defined regularity (rather
than coincidentally), will count as functionally equivalent.
Turing’s specific concern with logico-mathematical tasks aside, his style of
functionalist argument has a long pedigree in biology, where analogies in the functions of traits can be determined for phylogenetically unrelated species, whereas
sameness of kind depends on common descent of some trait – and only on common
descent. The underlying physiological structure might remain identical over the
course of generations, although both the function which it serves and its observable
shape may be subject to change if conditions to which that trait responds are altered.
The independence of functional from structural relations in biology was captured
in the conceptual distinction between “analogues” and “homologues” by Richard
Owen (1848). This distinction was put on an evolutionary footing by Charles Darwin, who provided vivid examples of homology himself when he asked:
What can be more curious than that the hand of a man, formed for grasping,
that of a mole for digging, the leg of the horse, the paddle of the porpoise, and
the wing of the bat, should all be constructed on the same pattern, and should
include the same bones, in the same relative positions?
(Darwin 1859, 434)
Hence, on the one hand, one ancestral form, for example a mammal’s forelegs,
may come to serve divergent functions – as wings in bats and arms in human
beings. On the other hand, one and the same function may come to be accomplished by structures of various degrees of similarity that have developed along
independent pathways in genealogically remote species – as for the structurally
similar but evolutionary independent lensed eyes in vertebrates and many Cephalopods, and the structurally dissimilar and equally independent compound eyes in
Arthropoda.
Competing with the steam drill in an epic battle at the height of the industrial age,
our folk ballad’s hero scored the costliest of victories. Exhausted from his successful race against the machine, John Henry was found “dying with his hammer
in his hand”. In this tragic manner, he has become an African American folk hero,
as a symbol of black workers’ struggle for respect in a society where many odds
were against them. One of these odds was the progressive displacement of their
labour by machines.
In keeping with Turing Machine functionalism, the previously quoted passage
suggests that such displacement normally works precisely because machines do
not reproduce or replicate human organic features and behavioural patterns, but
because they achieve the results of goal-directed human behaviours more quickly,
more effectively and more efficiently – or because they enable the achievement
of certain, hitherto unattainable, goals in the first place. The steam drill outlasted
John Henry not because it was like him, only stronger, more enduring, but because
it was very much unlike him. Hence, analogy in function does not require similarity in structure. Provided that the task in question is well-defined, any structure
that produces effects that result in the accomplishment of that task, and that produces these effects in accordance with an equally well-defined regularity (rather
than coincidentally), will count as functionally equivalent.
Turing’s specific concern with logico-mathematical tasks aside, his style of
functionalist argument has a long pedigree in biology, where analogies in the functions of traits can be determined for phylogenetically unrelated species, whereas
sameness of kind depends on common descent of some trait – and only on common
descent. The underlying physiological structure might remain identical over the
course of generations, although both the function which it serves and its observable
shape may be subject to change if conditions to which that trait responds are altered.
The independence of functional from structural relations in biology was captured
in the conceptual distinction between “analogues” and “homologues” by Richard
Owen (1848). This distinction was put on an evolutionary footing by Charles Darwin, who provided vivid examples of homology himself when he asked:
What can be more curious than that the hand of a man, formed for grasping,
that of a mole for digging, the leg of the horse, the paddle of the porpoise, and
the wing of the bat, should all be constructed on the same pattern, and should
include the same bones, in the same relative positions?
(Darwin 1859, 434)
Hence, on the one hand, one ancestral form, for example a mammal’s forelegs,
may come to serve divergent functions – as wings in bats and arms in human
beings. On the other hand, one and the same function may come to be accomplished by structures of various degrees of similarity that have developed along
independent pathways in genealogically remote species – as for the structurally
similar but evolutionary independent lensed eyes in vertebrates and many Cephalopods, and the structurally dissimilar and equally independent compound eyes in
Arthropoda.