A surprisingly complex anaphora resolution task in an article (about the relation between the Virginia Tech shootings and the issue of gun control) in this week's issue of The Economist, pointed out to me by Barbara Scholz:
The academic debate about whether guns save more innocent lives than they cut short, or vice versa, may never end. Most Americans are inclined to believe the latter.
How, in detail, do we understand the latter? I can explain; but it is by no means trivial.
The anaphoric phrases the former and the latter are used to refer back to, respectively, the first and the second of a pair of entities or propositions mentioned in the immediately preceding discourse. But here the use of the latter refers back to a proposition that superficially isn't there in the immediately preceding discourse. To find that proposition, you have to unpack the meaning of vice versa to get a second proposition.
The phrase vice versa denotes a proposition that is obtained by taking some proposition in the immediately preceding discourse that involves some binary relation, and constructing another that has the arguments of the relation the other way round. That is, you have to find a proposition (stated or implied) that says aRb, and then read vice versa as bRa.
In the quoted passage the obvious candidate is to be found in the clause whether guns save more innocent lives than they cut short, where we can take as our relation R the relation > (greater than) on the natural numbers. To say that guns save more innocent lives than they cut short is to say that where guns save i innocent lives and guns cut short j innocent lives, i > j.
So the vice versa operation on "where guns save i innocent lives and guns cut short j innocent lives, i > j" yields "where guns save i innocent lives and guns cut short j innocent lives, j > i". Or to put it more simply in plain prose, from the meaning "guns save more innocent lives than they cut short", the vice versa operation yields the meaning "guns cut short more innocent lives than they save".
What the latter picks up on is the second of two parts of the prior discourse. In this case, assuming the vice versa operation to be already done, the two parts are (1) the clause guns save more innocent lives than they cut short and (2) the clause whose meaning the interpretation of vice versa provides. So The Economist is claiming that most Americans believe guns cut short more innocent lives than they save.
Do you ever find yourself marveling at the fact that we can do this kind of computation — that there is anyone at all who can understand the kind of prose found in articles in The Economist? I often marvel at it. It's something no chicken can do, I can tell you that much.
Posted by Geoffrey K. Pullum at April 22, 2007 12:04 AM