in terms of. This much-debated three-word sequence is now widely called a complex preposition, joining such long-established sequences as in aid of, in front of, in place of; in common with, in compliance with; in exchange for; in relation to. It has also been called a “vague all-purpose connective” by one usage writer (H. P. Guth) in 1985, and “it encounters a great deal of criticism when used to speak of one ill-defined thing in terms of another equally vague and ill-defined” (Columbia Guide to Standard American English, 1993). It was rather extravagantly described by the Oxford philosopher Michael Dummett as “representing the lowest point so far in the present degradation of the English language”. Examples (from “broadcasters and military and government spokesmen”) cited by Dummett include: We have made great progress in terms of the balance of payments (rewrite, says Dummett, as The balance of payments has improved); Our troops have been highly successful in terms of advancing into enemy territory (read Our troops have advanced deep into enemy territory).
How did this complex preposition come into being? The OED [Oxford English Dictionary] reveals that it has been in use since the mid-18c. as a mathematical expression “said of a series…stated in terms involving some particular (my emphasis) quantity”, and illustrates this technical usage by citing examples from the work of Herbert Spencer (1862), J. F. W. Herschel (1866), and other writers. From this technical use came at first a trickle and, after the 1940s, a flood of imitative uses by non-mathematicians. The OED lists the phr. to think in terms of (and labels it colloq.) “to make (a particular consideration) the basis of one’s attention, enquiries, plans, etc.”: e.g. The impact of Ibsen…did much to revitalize the degenerate English theatre and force it to think in terms of living ideas and contemporary realities—J. Mulgan and D. M. Davin, 1947. And it is a simple matter to collect examples of in terms of which have been written, like this example, by people who are not “broadcasters and military and government spokesmen”: e.g. Dataquest pegs ESRI as the leading GIS company—in terms of both revenue and reputation—Computer Graphics World, 1988; He deals with the converso judaizing world in terms of its social and religious rituals, births, marriages, deaths, leading to the establishment of the Inquisition—Bull. Hispanic Studies, 1990; Rameau…conceived his music precisely in terms of timbres, types of attack, degree of sostenuto—Country Life, 1990; Justifying space in terms of material wealth is as ridiculous as saying that man went to the Moon merely to be able to return with velcro zips and non-stick frying pans—New Scientist, 1991. The dating of his novels in terms of when they were written rather than when they were published is often uncertain, since in the upheavals of exile some were not published chronologically—NY Rev. Bks., 1991. One can only conclude that there is a world outside the language of broadcasters and military and governmental spokesmen where the complex preposition in terms of is a useful particularizing device. But it should not be used merely as a “vague all-purpose connective”, as it seems to be in the following example: When John Major emerged as a possible candidate to lead the Conservative party, one was struck by his engaging artlessness in terms of class—Daily. Tel., 1991.
The New Fowler’s Modern English Usage, edited by R. W. Burchfield, 1996.