Who controls the sort order?
(From Wikipedia)
1) Natural order within the data itself:
The order is part of the Model, so it should go there. A raw pull of "all data" would return the data in the sorted order, and there is no interface to choose the sort order.
2) The user should control how they see the data:
The View would provide an interface (such as ascending/descending arrows) that interact with the Controller, and the Model understands the data well enough to do the requested sort on the data. However, a raw pull of the data doesn't necessarily have to be sorted, unlike in (1).
In either case,
The View doesn't understand that there's a sort going on, other that the ability to show which sort direction has been chosen. Don't put the logic there.
Small caveat
The sorting functionality could go purely in the View, under one circumstance (that I can think of offhand; there may be more):
A "dumb" sort where all the data is already in the view and it doesn't have to use any domain knowledge to do the sort. Very simple string or number comparison, for example. This is not possible in, for example, search results on a webpage when results are likely to be split across multiple pages.
