Part The last years of the eighteenth century are broken by a discontinuity similar to that which destroyed Renaissance thought at the beginning of the seventeenth; then, the great circular forms in which similitude was enclosed were dislocated and opened so that the table of identities could be unfolded; and that table is now about to be destroyed in turn, while knowledge takes up residence in a new space a discontinuity as enigmatic in its principle, in its original rupture, as that which separates the Paracelsian circles from the Cartesian order.