Only engineering is capable of analyzing the nature of a machine in terms of the successful working of the whole; phy...

shunhe on January 1, 2020

Hi @mamie,

The question here is asking us for an assumption required by the analogy, and so we should read the stimulus with a focus on the analogy presented. The stimulus tells us that engineering can analyze a machine's nature in terms of the successful working of the whole, whereas physics and chemistry can't express a notion of purpose. Similarly, physiology can analyze an organism's nature in terms of organs' roles in the body's healthy functioning. The analogy here is clearly between engineering and physiology. If we want, we can express it as

Engineering : Analyze successful working of whole of machine, which expresses a notion of purpose :: Physiology : Analyze organs' roles in body's healthy functioning

What do we need to assume in order for the analogy to be valid? It seems likely that the answer will have something to do with the idea of comparing machines and their purposes to organs and bodies and their purposes, and indeed, this is what (C) tells us. (C) makes explicit the assumption that "purpose" as used by engineers has an analog in organisms. Let's negate this assumption; if the engineer's notion of purpose doesn't have an analog in organisms, then the analogy cannot stand, as an important part of the analogy is that engineering, unlike physics and chemistry, can encompass this sense of purpose. Going back to the more compact analogy expression, the original analogy was actually

Engineering : Analyze successful working of whole of machine, which expresses a notion of purpose :: Physiology : Analyze organs' roles in body's healthy functioning (which also expresses a notion of purpose)

The other answer choices simply do not provide this assumption. (A), for example, is not a required assumption; the extent to which a hand or heart functions like a machine has no bearing on the analogy. (B), too, isn't a required assumption for the analogy. It doesn't really play a role in the analogy, and (D) and (E) are wrong for similar reasons. Hope this helps! Feel free to ask further questions if anything is still confusing.