Method of Fluxions was a book by Isaac Newton. The book was completed in 1671, and published in 1736. Fluxions is Newton's term for differential (and fluents for integral) calculus. He originally developed the method at Woolsthorpe Manor during the closing of Cambridge during the Great Plague from 1665 to 1667, but did not choose to make his findings known (similarly, his findings which eventually became the Philosophiae Naturalis Principia Mathematica were developed at this time and hidden from the world in Newton's notes for many years) until Gottfried Leibniz published his own version of the calculus, developed independent of Newton (though there are some indications that Newton's tendency to give cryptic hints on this subject may have assisted Leibniz there is no doubt that he developed the calculus independently), years later.

Newton's Method of Fluxions was formally published posthumously, but following Leibniz's publication of the calculus a bitter rivalry erupted between the two mathematicians over who had developed the calculus first and so Newton no longer hid his knowledge of fluxions.

See also

• History of calculus