In Lewis’ Screwtape Letters we read from the pen of Uncle Screwtape:
The whole philosophy of Hell rests on recognition of the axiom that one thing is not another thing, and, specially, that one self is not another self. My good is my good and your good is yours. What one gains another loses. Even an inanimate object is what it is by excluding all other objects from the space it occupies; if it expands, it does so by thrusting other objects aside or by absorbing them. A self does the same. With beasts the absorption takes the form of eating; for us, it means the sucking of will and freedom out of a weaker self into a stronger. ‘To be’ means ‘to be in competition’.
Now the Enemy’s philosophy is nothing more nor less than one continued attempt to evade this very obvious truth. He aims at a contradiction. Things are to be many, yet somehow also one. The good of one self is to be the good of another. This impossibility He calls love, and this same monotonous panacea can be detected under all He does and even all He is- or claims to be. Thus He is not content, even Himself, to be a sheer arithmetical unity; He claims to be three as well as one, in order that this nonsense about Love may find a foothold in His own nature.
~ Letter 18
That Lewis is able to so easily and pastorally interact with Heidegger is impressive in its own right. That he also manages to bolster Augustine’s concept of the unity of Trinity as love is icing on the cake.