The calculus of probabilities, when confined within just limits, ought to interest, in an equal degree, the mathematician, the experimentalist, and the statesman.

The calculus of utility aims at supplying the ordinary wants of man at the least cost of labour.
william stanley jevonsPLEASURE and pain are undoubtedly the ultimate objects of the calculus of economics. To satisfy our wants to the utmost with the least effort  to procure the greatest amount of what is desirable at the expense of the least that is undesirable  in other words, to maximize pleasure, is the problem of economics.
william stanley jevonsGeometric calculus consists in a system of operations analogous to those of algebraic calculus, but in which the entities on which the calculations are carried out, instead of being numbers, are geometric entities which we shall define.
giuseppe peanoFor each successive class of phenomena, a new calculus or a new geometry, as the case might be, which might prove not wholly inadequate to the subtlety of nature.
henry john stephen smithI never failed in mathematics. Before I was fifteen I had mastered differential and integral calculus.
Albert EinsteinFermat applied his method of tangents to many difficult problems. The method has the form of the nowstandard method of differential calculus, though it begs entirely the difficult theory of limits .
Morris KlineThe change began with John Stuart Mill and the Utopians . When Mill pointed out that economics had no ultimate solution to the problem of distribution , that society might do with the fruits of its toil as it saw fit, he introduced into the mechanical calculus of the market a conflicting calculus of moral judgment.
robert heilbronerThe cookbook gives a detailed description of ingredients and procedures but no proofs for its prescriptions or reasons for its recipes; the proof of the pudding is in the eating. ... Mathematics cannot be tested in exactly the same manner as a pudding; if all sorts of reasoning are debarred, a course of calculus may easily become an incoherent inventory of indigestible information.
george pólyaMy point is that the enterprise engineer uses, or is guided by, all of the concepts in the above list as may be appropriate to the specific task at hand; in many design tasks good citizenship, psychology, or ethics is more important than good calculus in achieving the optimumsolution or design. The preceding recommendations are intended primarily for Engineering Schools where already the student is trained and the faculty is experienced in methods of science and in the analysis and design functions.
The effects of heat are subject to constant laws which cannot be discovered without the aid of mathematical analysis. The object of the theory is to demonstrate these laws; it reduces all physical researches on the propagation of heat, to problems of the integral calculus, whose elements are given by experiment. No subject has more extensive relations with the progress of industry and the natural sciences; for the action of heat is always present, it influences the processes of the arts, and occurs in all the phenomena of the universe.
joseph fourierThe calculus was the first achievement of modern mathematics and it is difficult to overestimate its importance. I think it defines more unequivocally than anything else the inception of modern mathematics; and the system of mathematical analysis, which is its logical development, still constitutes the greatest technical advance in exact thinking.
APL is the first language not based on the lambda calculus that is not wordatatime and uses functional programming forms. Unfortunately, however, APL still splits programming into a world of expressions and a world of statements. Thus the effort to write oneline programs is partly motivated by the desire to stay in the world of expressions.
Israel is the Middle East’s only legitimate democracy, surrounded by cadres, warlords and villains that do not respect democracy or human rights. These bellicose nations jealously regard Israel, envying its success, stability, and might. Israel faces an impossible calculus between defending itself and facing angry outcries or risking its own destruction.
I have no fault to find with those who teach geometry. That science is the only one which has not produced sects; it is founded on analysis and on synthesis and on the calculus; it does not occupy itself with the probable truth; moreover it has the same method in every country.
If one looks at the different problems of the integral calculus which arise naturally when one wishes to go deep into the different parts of physics , it is impossible not to be struck by the analogies existing.
Science is turning into a monastery for the Order of Capitulant Friars. Logical calculus is supposed to supersede man as moralist. We submit to the blackmail of the 'superior knowledge' that has the temerity to assert that nuclear war can be, by derivation, a good thing, because this follows from simple arithmetic.
stanisław lem