A reader writes,

The other day I heard a radio commentator constantly using the phrase “in that calculus”, something I’d never heard before. [The] commentator was using it in a political context, pretty much as a fancy way of saying “in that situation”; I’d be grateful if you could look into it and cover it some time!

*Calculus* is one of those words like *parameter* and *paradigm* that have been yanked from their habitual scientific contexts into the general vocabulary by non-scientists to make their utterances sound more profound.

In the context of mathematics, the word *calculus* is usually preceded by *differential* or *integral*:

integral calculus: a branch of mathematics concerned with the theory and applications (as in the determination of lengths, areas, and volumes and in the solution of differential equations) of integrals and integration.

differential calculus: a branch of mathematics concerned chiefly with the study of the rate of change of functions with respect to their variables especially through the use of derivatives and differentials.

*Calculus* is the diminutive of Latin *calx*, “stone.” A *calculus* was a little stone or pebble. The plural, *calculi* gives us the word *calculation* because pebbles were used for counting. *Calculi* were also used as game pieces and for voting.

In the context of medicine, *calculus* is a hard deposit that builds up in the body to produce kidney stones, plaque, and such.

The word *calculus* is now to be found in a variety of contexts:

Competition along routes is just one variable in that calculus. (The context is a discussion of the process of airline pricing.)

They are casting Ellsworth as an unwilling enabler who will further an agenda even though he might not fully support it. And, in that calculus, his vote for Speaker of the House comes first and foremost.

No medical intervention is 100% safe. However vaccines are remarkably safe…It is risk versus benefit and in that calculus vaccines win.

J. C. Watts Endorsing Newt Gingrich is Awful Political Calculus

In New Calculus on Smoking, It’s Health Gained vs. Pleasure Lost

The political calculus on immigration reform changes day by day, but the moral calculus has not.

It seems to me that in each of these examples, *situation*, *calculation*, or *thinking* would serve the context.

Gregory Keyes wrote a great book titled “A Calculus of Angels.”

Words have meanings. When they are used in a manner contrary to their meanings, conflict ensues.

Well, this pretentious political jargon seems like to have been going viral these days, since I have noticed by chance one blatant instance right here earlier today while reading NYT:

“In Iran, the calculus is more complex. With oil prices dropping, the economic damage done by the sanctions is being amplified.”

Good catch, Maeve. I think this is a simple case of the word calculus being misused as a synonym for the noun calculation, just because it “sounds like it would mean that.” All the examples work with the actual word calculation:

Competition along routes is just one variable in that calculation.

They are casting Ellsworth as an unwilling enabler who will further an agenda even though he might not fully support it. And, in that calculation, his vote for Speaker of the House comes first and foremost.

No medical intervention is 100% safe. However vaccines are remarkably safe…It is risk versus benefit and in that calculation vaccines win.

J. C. Watts Endorsing Newt Gingrich is Awful Political Calculation

In New Calculation on Smoking, It’s Health Gained vs. Pleasure Lost

The political calculation on immigration reform changes day by day, but the moral calculation has not.

You are quite correct venqax.

Furthermore, that body of knowledge that is used by mathematicians, engineers, and scientists is sometimes called “The Calculus” to distinguish it from the kind of calculus that dentists and their aides fight all the time!

D.A.W.