Where do we begin?

Spinoza once wrote, “The scholastics start from things, Descartes from thought; I start from God.” And, as Étienne Gilson observed, “He [Spinoza] could not have said anything more true, and the name of Spinoza is enough to remind us why in fact the scholastics do not start from God.” But, where do Thomists start? Do we start with Thomas Aquinas himself? Perhaps, with his works? Which interpretation does a Thomist follow? Or, do we begin with contemporary concerns? As Gilson correctly points out, one glimpse at Spinoza reminds us why methodology, and the starting point of inquiry, remains so important to philosophy.  
To be clear: recognizing methodology is not ceding ground to epistemological relativists, it is taking seriously the human person and historicity. 
The problem of where we begin reminds me of another very old problem. Most analytical philosophers will have you begin philosophy with epistemology, what is your basic belief(s) is the question you will be asked. And yet, I cannot think of a question more akin to the heart of Descartes. The clever (and theistic) analytical philosophers will say you begin with metaphysics and the existence of God. But, if they are truly analytical philosophers, you can push back and ask why start there? And then suddenly you are thrown epistemological answers again, reliablism or coherence theory. What truly, really, is first philosophy? For analytical philosophers it is epistemology (or at least, theistic epistemology). 
For many continental philosophers first philosophy is epistemology as well, although hidden within the contours of the self. Do we begin with the ego or the primordial grounding of the self? Where do we begin these continental thinkers ask themselves? We begin by peeking into the limited contours of the individual.
Heidegger saw this dual (analytical and continental) problem as alienation, specifically an utter failure to see ourselves as persons.
 He was right.