Sentence Correction

lunarpower wrote:

GMATMadeEasy wrote: OA is A; I just want to understand why we do not use past perfect here because what they thought is after the fact mentioned in the sentence.Or rather i could say the fact mentioned and the action thought were at the same time , so past perfect is not justified.

we don't use the past perfect because that's what the geologists actually thought was true at that time.

if you wrote "they thought that X had been xxxxxx", then the implication is that they thought that X had *once* been xxxxxx, at some time previous to the time at which they had those thoughts.

e.g.

when i was a child, i thought that mickey mouse was president --> i thought that mickey mouse was actually president at the time i had these thoughts.
when i was a child, i thought that mickey mouse had been president --> i thought that mickey mouse had been a *previous* president.

lunarpower wrote:

GMATMadeEasy wrote:thanks Ron. I see here what is going on . let me isolate the situation :

My question is for a situation when we could use past perfect but would prefer past simple .

example -- modificaton of OG example -- . I modified the question this way to make the explanations above inapplicable.

His studies of ice-polished rocks in his Alpine homeland led Louis Agassiz in 1837 to propose the concept that ice sheets existed in now currently temperate areas.

His studies of ice-polished rocks in his Alpine homeland led Louis Agassiz in 1837 to propose the concept that ice sheets had existed in now currently temperate areas.

upon further consideration, i don't think that the past perfect is acceptable in this sentence.
here's why:
the concept (which is independent of the time at which it was proposed) is that ice sheets existed in *now* temperate areas -- in other words, this is a concept that only refers to NOW vs. THE PAST, and contains no explicit past time reference upon which the usage of the past perfect can be based.

on the other hand, if the sentence were written in such a way that agassiz's 1837 proposal were the past time reference, then you *could* use the past perfect. for instance,
louis agassiz proposed in 1837 that ice sheets had existed... in areas that had become temperate.
--> this is a correct sentence; notice that both usages of the past perfect rely upon 1837 as the explicit past time reference.

because the original sentence doesn't relate "had existed" directly to another past point in time, "had existed" doesn't work.

--
.

His studies of ice-polished rocks in his Alpine homeland led Louis Agassiz in 1837 to propose the concept that ice sheets had existed in now currently temperate areas.
upon further consideration, i don't think that the past perfect is acceptable in this sentence.
here's why:
the concept (which is independent of the time at which it was proposed) is that ice sheets existed in *now* temperate areas -- in other words, this is a concept that only refers to NOW vs. THE PAST, and contains no explicit past time reference upon which the usage of the past perfect can be based.

lunarpower wrote:

mundasingh123 wrote: Doesnt "led Louis Agassiz in 1837 to" serve as past reference point ."led" is in past tense.The sentence implies that the ice sheets existed before the studies led Louis Agassiz to propose .

i see what you're saying here, but the reference to "now temperate areas" anchors this fact in the present -- i.e., the idea persists into the present -- even though agassiz's work was in the past. (i explained this in more detail in the post above.)

upon further consideration, i don't think that the past perfect is acceptable in this sentence.
here's why:
the concept (which is independent of the time at which it was proposed) is that ice sheets existed in *now* temperate areas -- in other words, this is a concept that only refers to NOW vs. THE PAST, and contains no explicit past time reference upon which the usage of the past perfect can be based.

on the other hand, if the sentence were written in such a way that agassiz's 1837 proposal were the past time reference, then you *could* use the past perfect. for instance,
louis agassiz proposed in 1837 that ice sheets had existed... in areas that had become temperate.
--> this is a correct sentence; notice that both usages of the past perfect rely upon 1837 as the explicit past time reference.

because the original sentence doesn't relate "had existed" directly to another past point in time, "had existed" doesn't work.