Wrong. The hands are not busy with or upon each other, but with or upon the work. As commonly would be ambiguous here, equally or alike should be used, or simply both. Mutually serviceable, again, would have been right.
There were other means of communication between Claribel and her new prophet. Books were mutually lent to each other.—Beaconsfield.
This surprising sentence means that Vanity Fair was lent to Paradise Lost, and Paradise Lost to Vanity Fair. If we further assume for politeness' sake that mutually is not mere tautology with to each other, the only thing left for it to mean is by each other. The doubt then remains whether (1) Paradise Lost was lent to Vanity Fair by Paradise Lost, and Vanity Fair to Paradise Lost by Vanity Fair, or (2) Paradise Lost was lent to Vanity Fair by Vanity Fair, and Vanity Fair to Paradise Lost by Paradise Lost. This may be considered captious; but we still wish the author had said either, They lent each other books, or, Books were lent by them to each other.
A thing is unique, or not unique; there are no degrees of uniqueness; nothing is ever somewhat or rather unique, though many things are almost or in some respects unique. The word is a member of a depreciating series. Singular had once the strong meaning that unique has still in accurate but not in other writers. In consequence of slovenly use, singular no longer means singular, but merely remarkable; it is worn out; before long rather unique will be familiar; unique, that is, will be worn out in turn, and we shall have to resort to unexampled and keep that clear of qualifications as long as we can. Happily it is still admitted that sentences like the two given below are solecisms; they contain a self-contradiction. For the other regrettable use of unique, as when the advertisement columns offer us what they call unique opportunities, it may generally be assumed with safety that they are lying; but lying is not in itself a literary offence, so that with these we have nothing to do.
