Bahnsen's response would be precisely this: unless you presuppose the Christian worldview, you have no basis for the inductive principle and if you have no basis for the inductive principle, then you can make nothing intelligible.
In summary, It is as if we must first settle our epistemic differences with the unbeliever, and only then, is he or she ready to listen to what Scripture says. To put it another way, Bosse seems to be saying that Scripture is accessible by way of the natural mind apart from God. In other words, Scripture is powerless to change the mind spiritually until the apologist has done so intellectually, philosophically, rationally. One word: poppycock.