Full Idea
Both rationalists (who start with a priori truths and make deductions) and empiricists (starting with indubitable sense data and what follows) would guarantee truth, but neither even begins to account for scientific knowledge.
Gist of Idea
Neither a priori rationalism nor sense data empiricism account for scientific knowledge
Source
Paul Thagard (Coherence: The Price is Right [2012], p.46)
Book Reference
-: 'Southern Journal of Philosophy' [-], p.46
A Reaction
Thagard's answer, and mine, is inference to the best explanation, but goes beyond both the a priori truths and the perceptions.