Editing Inertia (section)

===Theory of impetus===
{{Main|Theory of impetus}}
{{See also|Conatus}}

In the 14th century, [[Jean Buridan]] rejected the notion that a motion-generating property, which he named ''impetus'', dissipated spontaneously. Buridan's position was that a moving object would be arrested by the resistance of the air and the weight of the body which would oppose its impetus.<ref>Jean Buridan: Quaestiones on Aristotle's Physics (quoted at [https://web.archive.org/web/20110720105959/http://brahms.phy.vanderbilt.edu/a203/impetus_theory.html Impetus Theory])</ref> Buridan also maintained that impetus increased with speed; thus, his initial idea of impetus was similar in many ways to the modern concept of momentum. Despite the obvious similarities to more modern ideas of inertia, Buridan saw his theory as only a modification to Aristotle's basic philosophy, maintaining many other [[Peripatetic school|peripatetic]] views, including the belief that there was still a fundamental difference between an object in motion and an object at rest. Buridan also believed that impetus could be not only linear but also circular in nature, causing objects (such as celestial bodies) to move in a circle. Buridan's theory was followed up by his pupil [[Albert of Saxony (philosopher)|Albert of Saxony]] (1316–1390) and the [[Oxford Calculators]], who performed various experiments which further undermined the Aristotelian model. Their work in turn was elaborated by [[Nicole Oresme]] who pioneered the practice of illustrating the laws of motion with graphs.

Shortly before Galileo's theory of inertia, [[Giambattista Benedetti]] modified the growing [[theory of impetus]] to involve linear motion alone:

{{quote|[Any] portion of corporeal matter which moves by itself when an impetus has been impressed on it by any external motive force has a natural tendency to move on a rectilinear, not a curved, path.<!--><ref>Giovanni Benedetti, selection from ''Speculationum'', in [[Stillman Drake]] and I. E. Drabkin, ''Mechanics in Sixteenth-Century Italy'' [[University of Wisconsin Press]], 1969, p. 156.</ref>{{Failed verification|date=October 2022|reason=The citation for this passage appears to be incorrect.  It is not on p. 156 of Drake and Drabkin, and apparently not anywhere in the book.}}<--><ref>Stillman Drake. ''Essays on Galileo etc.'' Vol 3. [https://books.google.com/books?id=dKEqrYdQ0I0C&q=%22Fourth,%20any%20portion%22 p. 285.]</ref>}}

Benedetti cites the motion of a rock in a sling as an example of the inherent linear motion of objects, forced into circular motion.