“Philosophy of religion” is a concept that literally means the opposite of its established meaning.

After all when you say philosophy of religion it is assumed that you are referring to an activity where religion is subjected under the examination of philosophical reason. In other words: philosophy is the active agent and religion is the object of philosophical study.

But we may also argue that all philosophy is presupposed by belief systems. Religion is not only a belief system obviously (it is also a system of practices) but when we examine any proposition, what counts is the nature of that proposition in terms of what can be known and how it is known. We examine it differently if the proposition is in the context or religion or some other context. Means to challenge that “contamination” of context and the presuppositions that come with it are exactly the power of philosophy. The power of philosophy is to demonstrate that when you probe the conceptual understanding deep enough these distinctions of philosophy and religion may even vanish at the same time as they become more defined. That is the power of conceptual deconstruction and I guess it is inherent in the language itself or perhaps it is the feature of relationship between language and reality.

That means that any philosophy is “philosophy of religion” in the literal sense that is in the opposite sense of what is the established meaning of it.

Let me rephrase that: every science, every religion, every philosophy can be reduced to its fundamental presuppositions that reveals the limits of certainty of knowledge. It is the grey area where beliefs, superstitions, myths and religions intermingle mostly unconsciously in the individual psyche or in our culture, in what is the foundation of “accepted truth”.

It is a dilemma – an impasse – from the point of view of reason. But from the point of view of life, being, existence, experience and such like it is not necessarily a problem. It is problem only in the patterns of thinking.

And of course the same thing applies if we say

“philosophy of love”
“philosophy of life”
“philosophy of knowledge”
“philosophy of human reason”
“philosophy of morals”

But “philosophy of religion” demonstrates this perhaps more accentuated even if “philosophy of love” would do as well.

In this literal meaning the history of philosophy is “philosophy of human reason”.

What of the territory where reason, knowledge and beliefs are in the state of vague definition because of human limitations? That is where we can not escape the literal meaning of that approach regardless of how you name it (be it “philosophy of love, life or religion”).

Something other than human reason dictates the limits of what can be comprehended.

I guess I could have just said that it is the flip side of Buddhist philosophy, Taoist philosophy, Hindu philosophy etc.