The geometric origin of perspectivist science in G.W. Leibniz. Analysis based on unpublished manuscripts (Q2041103)

In his \textit{Discours de Métaphysique} (1686) Leibniz refers to the theory of perspective: ``several spectators believe that they are seeing the same thing and agree among themselves about it, even though each sees and speaks in accordance with his view''. That is one of the reasons why the authors discuss three unpublished manuscripts on perspective written by Leibniz between 1679 and 1686. The first one is \textit{Constructio et usus scalae perspectivae}. It is on the method of perspective scales in the plane of the representation: a horizontal equidistant scale on the ground line and a second vertical scale measuring the foreshortening. Leibniz constructs the image of a cube. \textit{Origo regularum artis perspectivae} constitutes according to the authors a decisive step in Leibniz' research in the direction of general rules. Leibniz gives formulae to determine the coordinates in the tabula of a point in space. And in \textit{Scientia perspectiva} he gives his final view on the subject and simplifies his formulae.