"First of all, if we speak of two powers, and if we do so in cases where it becomes necessary for various reasons to maintain a certain external symmetry between them, we prefer to use the word 'authority' rather than the word 'power' for the spiritual order. The word 'power' can then be reserved for the temporal order, to which it is better suited when taken in its strictest sense. In fact, the word 'power' almost inevitably evokes the idea of strength or force, and above all the idea of a material force, a force which manifests itself visibly and outwardly and affirms itself by the use of external means, for such means indeed characterize the temporal power by very definition. On the contrary, spiritual authority, interior in essence, is affirmed only by itself, independently of any sensible support, and operates as it were invisibly. If we can speak in this context of strength or force, it is only by analogical transposition, and, at least in the case of a spiritual authority—in its purest state so to speak—it must be understood that it is an entirely intellectual strength whose name is 'wisdom' and whose only force is that of truth."