"There is no such thing as a 'brute fact.'"
I had a quibble with this from the get go, but the more I thought about it, the less I bought it.
Are we being told to accept the statement "there is no such thing as a 'brute fact'" itself as a 'brute fact?' If so, then it is necessarily false by its own assertion.
If not, then the statement is a statement of opinion or interpretation that is informed by a particular worldview.
But is it a Christian worldview?
Romans 1:18 "The wrath of God is being revealed from heaven against all the godlessness and wickedness of men who suppress the truth by their wickedness, 19 since what may be known about God is plain to them, because God has made it plain to them. 20 For since the creation of the world God's invisible qualities—his eternal power and divine nature—have been clearly seen, being understood from what has been made, so that men are without excuse."
I think not. Don't get me wrong. I think presuppositional apologetics is powerful and necessary.
However, I think that often the presuppositionalist rejects out of hand the classical apologist's work on a false fear of syncretism creeping into Christian doctrine. I suppose there would be a need to stay on guard over what ought to be viewed as general revelation and what is reserved for special revelation. A good classical apologist doesn't sink to or lower oneself to a role of accommodation. Rather, they lift the other up so as to allow them to peer out from the ledge of the Christian worldview in order to see the sweeping beauty and perspective that we have in Christ.
Likewise, many classical apologists might see presuppositionalism as a doorway to relativism and postmodernism, especially with regard to the area of epistemology. I don't think that it is a necessary outworking of the presuppositional approach, but it can very easily become one (such as Frame's perspectival view of the knowledge, where truth is not seen as something transcendent and outside of us, but instead a combination of our normative, situational and existential environment. By contrast, a classical apologist would view actual knowledge and truth as outside of the influences of these perspectives.).
Instead, I see 1 Peter 3:15 as a great balance for the two approaches:
But in your hearts set apart Christ as Lord. Always be prepared to give an answer to everyone who asks you to give the reason for the hope that you have. But do this with gentleness and respect