To understand the nature Of these partial observers that swarm
through all the sciences and systems of reference, we must avoid
giving them the role of a limit of knowledge or of an enunciative
subjectivity. It has been noted that Cartesian coordinates privilege
the points situated close to the origin, whereas those of projective
geometry gave "a finite image of all the values of the variable and the
function." But perspective fixes a partial observer, like an eye, at the
summit of a cone and so grasps contours without grasping reliefs or
the quality of the surface that refer to another observer position. As a
general rule, the observer is neither inadequate nor subjective: even
in quantum physics, Heisenberg's demon does not express the impossibility of measuring both the speed and the position of a particle on
the grounds of a subjective interference of the measure with the
measured, but it measures exactly an objective state of affairs that
leaves the respective position of two of its particles outside of the
field of its actualization, the number of independent variables being
reduced and the values of the coordinates having the same probability. Subjectivist interpretations of thermodynamics
As for the other aspect, creative or signed enunciation, it is
clear that scientific propositions and their correlates are just as signed
or created as philosophical concepts: we speak of Pythagoras's theo-
rem, Cartesian coordinates, Hamiltonian number, and Lagrangian
function just as we speak of the Platonic Idea or Descartes's cogito
