Thanks for the thoughtful article. It seems that "function" is a key concept here. A composite object can be considered as an instance of a type when it can function as that type. So, the three distinct pieces of the fishing pole (hook, line, and pole) can be considered a fishing pole when, with no further modification (e.g. no further tightening of the knots), the composite object can function as a fishing pole. The knots are tight enough to hold the pieces together when the fish hits the hook. Same for the machine gun. The definition uses the term "function". So a composite object of a semi-automatic rifle + bump stock can be considered a machine gun if it functions as a machine gun. Here the Supreme Court seems to have 1) admitted that such a composite object functions as a bump stock, and 2) found a way to distinguish a single pull of a trigger with a single pull of a trigger followed by holding the trigger in place. Your reference to Hitchen's "extraneous or irrelevant complexities" is spot on, in that it seems 2) is used to ignore the implications of 1).
Thanks for the thoughtful article. It seems that "function" is a key concept here. A composite object can be considered as an instance of a type when it can function as that type. So, the three distinct pieces of the fishing pole (hook, line, and pole) can be considered a fishing pole when, with no further modification (e.g. no further tightening of the knots), the composite object can function as a fishing pole. The knots are tight enough to hold the pieces together when the fish hits the hook. Same for the machine gun. The definition uses the term "function". So a composite object of a semi-automatic rifle + bump stock can be considered a machine gun if it functions as a machine gun. Here the Supreme Court seems to have 1) admitted that such a composite object functions as a bump stock, and 2) found a way to distinguish a single pull of a trigger with a single pull of a trigger followed by holding the trigger in place. Your reference to Hitchen's "extraneous or irrelevant complexities" is spot on, in that it seems 2) is used to ignore the implications of 1).