...тоска осталась необъяснённой, ибо не могла же её объяснить ... другая мысль.

Full sentence is too long for the title of a post:
'Она улетела, а тоска осталась необъяснённой, ибо не могла же её объяснить мелькнувшая как молния и тут же погасшая какая то короткая другая мысль: ' (Bulgakov again)

My poor attempt at translation yeilds this:
It flew off, but the gloom remained inexplicable, since it could not explain another 'flashing like lightning and then dying away' brief thought:

The 'proper' translation seems to be:
'It flew off, and the anguish remained unexplained, for it could not well be explained by another brief thought that flashed like lightning and at once went out;-'

But for this to be correct, I think объяснить would need to mean 'to be explained by' not 'to explain.'

I know my transalation is wrong as 'мелькнувшая как молния и тут же погасшая какая то короткая другая мысль' is nominative, not accusative case.

Does 'объяснить' mean 'to be explained by' here, if so, why? Or is it something else.

Thanks.

Looks like you forgot that in russian reordering of words is usual thing and grammatical case is the key to understanding relations between words.
"Я могу объяснить это" = "I can explain it"
"Меня может объяснить это" = "I can be explained by it"
"Это могу объяснить я" = "It can be explained by me"
"Это может объяснить меня" = "It can explain me"
P.S.
"...не могла (же) её(тоску) объяснить ... мысль" -> "anguish cannot be explained by ... thought"

P.P.S.
More examples:
Я объясняю это = I explain it
Это объясняю я = It is explained by me =(just reordering)= I explain it
but
Это объясняется мной = It is explained by me (verb is changed to "self-applied")
Я объясняюсь этим = I am explained by it (verb is changed to "self-applied")

Она улетела, It flew off /correct/
а but is closer than and by meaning
тоска there's no such exact word in English, it's more like anguish, not gloom.
осталась необъяснённой, kept/left/remained unexplained (passive)
ибо because
... мысль a ... thought
не могла её объяснить could not explain it.

Quote:

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The 'proper' translation seems to be:
'It flew off, and the anguish remained unexplained, for it could not well be explained by another brief thought that flashed like lightning and at once went out;-'

But for this to be correct, I think объяснить would need to mean 'to be explained by' not 'to explain.'

---

I don't understand what you're takling about :search:

My try (just rewording plainly closer to the original sentence meaning -- slightly changed clause order)
It flew off, but the anguish remained unexplained, because a brief thought ... , flashing like lightning and then dying away, could not explain this anguish.

Okay, it was word order that confused me. You're right Alex, I was stupid to overlook grammatical cases.

So:-

'It flew off, but the anguish remained unexplained, because another brief thought could not really explain it.'

Which, retaining the order of clauses in the original, becomes:-

'It flew off, but the anguish remained unexplained, since it could not well BE EXPLAINED BY ...another brief thought:-'

I need to remember to look at case first, then word order second, THEN work out how to express this in English word order. Not the other way around, or whatever I did with this sentence...

Thanks both.