If one is going to talk of a “Christian philosophy” and if one is going to define such along the lines of which B N Tatakis has done, then one is going to have to offer definitions, or to at least delimit, one’s terms: Christian, philosophy, truth, faith, even, perhaps, reason. One is also going to have to speak to the sort of paradigm of dialectical opposition which antithesizes faith and reason/philosophy/truth.
First, let’s begin with some terminological clarifications. One may well assume that Dr. Tatakis’ sense of Christianity in his definition is grounded in and contextualized by specifically Orthodox Christianity. But I have not only already indicated that I am going to use Tatakis more as a jumping off point than a critical examination of his view per se, one might also rightly assume Dr. Tatakis was aware that there are other Christian groups than the Orthodox Church. One can certainly discern a specifically Orthodox content to his “Christian philosophy” but his definition is itself more broad, and our current context is much more pluralistic.
It is precisely because of this that defining a specifically “Christian” philosophy today is perhaps impossible if one takes all claims to the name Christian as on equal footing. One either has to accept as identical two groups with antithetical metaphysics (those who accept the essence/energies distinction and those who accept absolute/definitional divine simplicity), or those who, while accepting the same metaphyics, hold antithetical positions on aspects of it (the Calvinist/Arminian debate on freedom of the will, or those who accept a position of moral guilt being attached to original sin and those who do not).
In this context, then, “Christian philosophy” does not appear to be susceptible to a common enough reduction that all could accept the definition. It appears, at this point, then, that one may have an Orthodox philosophy, or a Calvinist philosophy, or any other label. But given the radical differences between the Christian groups that do not admit of resolution, it does not appear that one can have a generically labeled “Christian” philosophy.
I will return to this question shortly. Because depending upon how one describes or defines “philosophy” it does not appear to me that any of these more specific Christian designations (Orthodox, Calvinist, etc.) can be legitimately combined with “philosophy,” either. That is to say, if one defines philosophy in more of a Hadotan sense, then I could conceive that one might argue one cannot have a Calvinist (Christian) philosophy. I would not be prepared to say that such an argument would be valid let alone persuasive. I’m just saying I could conceive of the point.
But first, and perhaps more importantly for this question, we need to understand what might be best meant by “philosophy.”