"It is obvious that the executive power could not proceed from the Parliament, made of two Houses and holding the legislative power, or we would have a mixing of powers in which the government would soon be nothing more than an makeshift of delegations. Certainly, during the current transitional period, we had to have the President of the provisional government elected by the National Constituent Assembly, because from a clean slate there was no other acceptable means to designate him. But this can only be a momentary arrangement. Truly, unity, cohesion and the internal discipline of the government of France must be sacred things, or the very direction of the country will become powerless and disqualified. How could this unity, this cohesion and this discipline be maintained if the executive power came from the other power which it must balance, and if each of the members of the government, which is collectively responsible to the entire national representation, was, at his post, only the representant of a party?"
January 1, 1970
https://en.wikiquote.org/wiki/Separation_of_powers