“A wheel that can be turned though nothing turns with it, is not part of the mechanism”—what about a gyroscope wheel that is a part of a stabilizing mechanism?
This comes to show, IMHO, two things: one should be extremely careful with one’s intuitions and examples must not be taken too far.
If you really wanted to nitpick, you could also point out non-driven wheels on cars. Such a wheel doesn’t turn anything useful itself (it is turned but does not turn anything), but it still successfully prevents one end of a vehicle from dragging on the ground, which is its actual purpose. But we’re merely amusing ourselves with literalistic counter-examples at this point, as I see you are well aware.
A bit off-topic:
“A wheel that can be turned though nothing turns with it, is not part of the mechanism”—what about a gyroscope wheel that is a part of a stabilizing mechanism?
This comes to show, IMHO, two things: one should be extremely careful with one’s intuitions and examples must not be taken too far.
If you really wanted to nitpick, you could also point out non-driven wheels on cars. Such a wheel doesn’t turn anything useful itself (it is turned but does not turn anything), but it still successfully prevents one end of a vehicle from dragging on the ground, which is its actual purpose. But we’re merely amusing ourselves with literalistic counter-examples at this point, as I see you are well aware.