Thank you, Annis.
No. This is one of the most confusing things about verb aspect — in interacts with the intrinsic meaning of the verb in complex ways. So, every verb has what we can call a "lexical aspect." That is, the meaning of the word itself can imply a time structure. For example, "sneeze" or "trip" are not things that we normally think of as actions that go on for very long. In the linguistics biz, we refer to the telicity (from τέλος) of the verb. "Trip" is telic, since it has a natural end-point, "walk" is atelic, since in theory it can go on for some time. (See the link above for more details and remaining theoretical questions around these.)
Do you have a Japanese colleague or friend ?
Japanese language has, like Greek, an extensive usage of verb aspect (like, much use and intermingling of past and perfect tenses when talking about a present time matter).
Though I am still a beginner in Greek, I feel Japanese and Greek are very similar in the use of aspoect.
Sometimes, when I literally translate the Greek into Japanese, the use of aspect, i.e. what it implies, is very understandable to me, a Japanese.
It may be easier for Japanese to learn about the Greek aspect than for English speakers.
So if you have a Japanese friend, try asking him how Japanese use asperct.
"To ti e^n einai", if it means "What it was to be", would imply in Japanese "What it was for us to be", or "What it meant for us (in some past time shared by us, like in our previous lecture, or in our customary use) to be".
By the use of a past tense, the questioner urges the hearers to be reminded of the past.As I always do at this point, I strongly urge people to get their hands on Rijksbaron's The Syntax and Semantics of the Verb in Classical Greek: An Introduction: Third Edition. It is still in print and inexpensive. He covers all these issues.
I will buy it, since Goodwin's Syntax of the moods and tenses of the Greek verb, which I have, seems to be similar to it but didn't answer my question this time.