French law is a code. In some ways it goes back to Roman law, but its direct ancestor is the Code Napoléon of 1804.
Napoleon, being not only French (well, sort of) but a product of the Enlightenment, believed in the power of reason to impose order (here meaning justice) from above on the chaos of life, the infinite number of situations that can arise and must be adjudicated. The result was a document. Here is its famous first page: