Theorist: To be capable of planned locomotion, an organism must be able both to form an internal representation of i...

Irina on November 4, 2019

@lerondagates,

Let's start by diagramming the stimulus.

To be capable of locomotion (A) an organism must be able to form representation (B) and to send messages (C). Locomotion is a sufficient condition, and representation & messages are necessary conditions.

A- > B & C

Such an organism must have a central nervous system (D). This premise presumes that for an organism to be able to form representation/ send messages, it must have a central nervous system.

B&C -> D
A-> D

Thus an organism incapable of planned locomotion (A) does not have a central nervous system (D)

~A->~D

This is a flawed argument, the only proper inference is that:

~D ->~A
No nervous system -> no locomotion as nervous system is a necessary condition for locomotion.

(A) correctly points out the flaw - the argument confuses a necessary condition, i.e. central nervous system for an organism possessing capacity, i.e . locomotion with a sufficient one. Since the conclusion given in the stimulus is no locomotion - > no nervous system, this conclusion is reached from the following premise: nervous system -> locomotion, where nervous system is a sufficient condition for locomotion. But there is no such premise in the argument, instead we have a premise saying locomotion -> nervous system, where nervous system is a necessary condition - hence the conclusion confuses the necessary for sufficient condition.

Let me know if this makes sense and if you have any further questions.