When is no the right answer? At what point should determination crawl back into bed and save its strength for another fight? When is it okay to quit?

I had a final paper prompt handed to me with one week before its duedate. It was a 15 page paper and was 1/3 of the final grade. I slaved over it all week. It invaded my thoughts and kept me up at night and my mind was racing annoyingly fast. As the week progressed and I became more nervous about the paper, the actual writing became worse. I fuddled up drafts and deleted and added and cut and pasted and reworked so by the night before I had absolutely nothing worth handing in. I am very aware of my own writing so I know it was God awful. Some of the worst filth that's ever come out of my fingers. As it stood, the paper was due in 10 hours and I had nothing. My mind was drowning in what seemed like a dictionary of words that were alphabetized. At the time I saw two choices. Either I could start from scratch and power through one last draft that I wouldn't really have time to edit, but should at least be linear, or I could go to sleep and just turn in the filth I had written at the sake of my brain which was at the end of its circuit. I went to sleep. The next morning I got up and printed out the paper and turned in what I had. I did horribly but ended up doing okay in the class. I still don't know whether it was right of me to quit, but I also don't know how those 10 hours may have affected my mind.

I didn't use that example to ask you whether it was the right decision or not, because that was my decision and for better or worse it's already in the past. I used that example to illustrate the ambiguity and the degree of personal choice that is involved in quiting something. In my opinion, the only time we should quit is when it is entirely our own decision. We should take into account external forces and opinions and factors yes, but when it comes down to continuing or stopping, we as independent controllers of our mind and bodies need to ask ourselves what the right decision at the time is. In my case above, there was no right or wrong choice and I imagine a lot of times when the decision about quitting needs to be made, there is no right or wrong answer as well.

But might we compile a list of the most important factors in determining such a choice?

I think Safety must be the number one. I acted at the time out of safety, safety for my faltering psyche which I didn't think could handle 10 more hours in the midst of final week. Not only should it be safety for ourselves, but we must also take into account safety of others. When a commander in an army makes the decision to retreat, he does so primarily to save his soldiers and secondly for strategy.

But what are some others?  Nothing else immediately comes to mind. Maybe I should ask what are bad reasons to quit? Cowardice and laziness come to mind, but what else?

It all might be an impossible query for the decision to quit is almost always made in the moment. It is a split second choice to give up and maybe the final decision is always in answer to the moment. But what do you all think? When is quiting required and are there ever instances where you don't feel bad after giving up?