10 This society is made up of men, just as civil society is, and yet is supernatural and spiritual, on account of the end for which it was founded, and of the means by which it aims at attaining that end. Hence, it is distinguished and differs from civil society, and, what is of highest moment, it is a society chartered as of right divine, perfect in its nature and in its title, to possess in itself and by itself, through the will and loving kindness of its Founder, all needful provision for its maintenance and action. And just as the end at which the Church aims is by far the noblest of ends, so is its authority the most exalted of all authority, nor can it be looked upon as inferior to the civil power, or in any manner dependent upon it.
Source: Immortale Dei (Vatican.va)