What's the meaning of the phrase "at your duty" in this context?

Question

This is the context, from an English translation of Dostoyevsky's Crime and Punishment. The word "service" here means military service.

'Funny fellow!' pronounced the innkeeper. 'And why don't you work, why aren't you at your duty, if you are in the service?'

Now, I know that there's a phrase "on duty" which TFD defines as:

Engaged in or responsible for assigned work.

Also one of TFD's definitions for "duty" says:

c. Active military service: a tour of duty.

but military service is not a physical location but an abstract concept, therefore I'm confused about the usage of the preposition "at."

TFD lists one of the synonyms for "duty" as "job".

Does "why aren't you at your duty" mean "why aren't you at your job" (the physical job location)? or perhaps it's the same as "why aren't you on your duty?"

Can you use the preposition "at" when speaking about an abstract concept?

Answer 1

Your premise is not exactly correct; the "funny man" Marmeladov calls himself a titular counsellor, which was a rank in the Russian civil service at the time, not the military service. But the distinction is not very important in this case.

In the United States, there is a term duty station which refers to a civil servant's or military servicemember's habitual work location, the physical place where they perform their duties. Thus "at your duty" could be a shortening of "at your duty station" and refer to Marmelodov being physically at his assigned office. I am not sure if this term is common among other English-speaking countries or other languages.

But even if "duty" refers specifically to "daily work" (i.e. even if the question is not "Why are you not in your office?" but instead "Why are you not doing your job?"), the preposition at can be used:

at, preposition
5. Occupied in (activity).

men at work

6. In a state of.

She is at sixes and sevens with him.
They are at loggerheads over how best to tackle the fiscal cliff.
The city was at the mercy of the occupying forces.

Thus "at your duty" can mean "occupied in doing your duty" or "in a state of doing your duty."

I would say "at your duty" is kind of an old-fashioned usage and I wouldn't expect it to be said in common speech in a bar these days. Instead I would expect the bartender to ask "Why don't you work, why aren't you at your job?" or something like that.

Answer 2

It is an oddity of the translation.

Dostoesvsky uses "служите", literally "serve". A modern edition (the Nicolas Pasternak Slater translation) has this paragraph translated as:

Hey joker! Why don't you do some work? If you're a clerk, why aren't you at the office?

The Constance Garrett translation is a serious and useful book, and the translator was a skilled linguist. However it suffers for being over 100 years old (and so some of language is dated), and Garrett does make some errors in understanding the Russian. Here it seems that the Russian idiom is that officials "serve" [служить] rather than "work" [работаешь]. Which is a distinction that isn't quite the same in English. But part of Garrett's choice of the word "duty" is to preserve some of the Russian distinction.

You may compare with how Pasernak translates the same phrase.

Note that the questions are rhetorical, the bar owner knows the story that is told in the rest of the chapter, he is just trying to provoke the drunkard.