There are two ways I can make sense of that quote: first, by assuming that Lewis's "that which is false or unhelpful" has already been excluded by the time it reaches you, allowing you to turn your critical (by a conventional definition) faculties off and absorb a known-good set of data; and second, by shifting the burden of evaluation entirely to intuition and consciously accepting (humbly and uncommentatingly) only what feels intuitively sound. Neither seems suitable for what we're doing here; quite aside from any philosophical objections, we don't have a known-good set that's good enough to propagate without caveats, and the kind of knowledge we work with is very frequently counterintuitive.