# Was there some prior idea that inspired both Fermat & Descartes to invent coordinates?

It seems incredible to me that both Descartes & Fermat could have both simultaneously discovered such a novel & significant idea, without there being some single prior idea that they both could have taken inspiration from. Has there been any research done on this, or can someone expliciate the histrorical record further?

Wikipedia does state that Nicole Oresme in the 14C made constructions similar to coordinates. This is well before either Descartes or Fermat. It doesn't state whether they were influenced by him.

Alternatively, could they have been influenced by developments in Cartography or Map-making?

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 Maybe they inspired from the game of chess ;) – N. S. Jun 13 '12 at 16:53 @N.S.:Nice idea, it would be my preferred possibiity! – Mozibur Ullah Jun 14 '12 at 3:06

 Wikipedia has that Descarte/Fermat using only a single axis (which I find quite hard to imagine), with later workers adding the second axis. How did Ptolemys coordinate compare with the modern cartesian grid. Was it an exact analogue? – Mozibur Ullah Jun 14 '12 at 3:10 I've just checked wikipedia, and ptolemys coordinates were cartographical ( ie latitude/longitude), and mentioned in Geographia. It doesn't mention Geometry? – Mozibur Ullah Jun 14 '12 at 3:39 @MoziburUllah, oops that was a braino on my part. Of course it was Geography. – Henning Makholm Jun 14 '12 at 10:47 Perhaps this is a false analogy, but I am reminded of how people believe $E=mc^2$ was Einstein's famous discovery when it was really just a consequence of his actual discovery. Do you feel this is a fair analogy? – 000 Jun 14 '12 at 11:15 @Limitless: To some extent, yes; the truth is usually much more complex than what is presented as such by the popular mind. It does still present an aspect of the truth; in your example, the equivalence of mass & energy, is not just a consequence, but an very significant consequence. – Mozibur Ullah Jun 15 '12 at 0:01