How should the phrase "Let it be done" be interpreted grammatically?
What confounds me are the following assumptions, some or all of which may be wrong:
- "Let" implies imperative
- "it be done" implies a subjunctive
- the lack of an agent implies passive
- section 5 of this reference says that the "let" indicates the desire for a hypothetical situation and is hence part of the subjunctive - I'm thinking that this "let" could be either a desire and a command but at this point I'm probably wrong
Given the above is "Let it be done" a correct passive transformation of "Do it"? Is this a passive-voice imperative-mood construction (in which case what about the subjunctive?), is it a passive-voice subjunctive-mood construction? Is it somehow in the active voice ?
The original query was intended for "Let the cake be eaten", which I had assumed to be a passive transformation of "eat the cake" the title and rest of the question are an attempt at generalization. Also note that I'm looking at this from a purely grammatical point of view, whether such constructions are silly or not is another matter.