Purpose: In this article, I question how practitioners can balance the certainty and confidence that they can help their patients with the uncertainty that makes them continually question their beliefs and assumptions. Method: I compare the mechanisms of science and models of clinical practice that may help practitioners achieve the right balance between total acceptance of the status quo and an open willingness to explore and accept new ideas. Conclusion: Clinical practice, unlike science, has no independent self-correction mechanism that leads to consensus about best clinical practices. Evidence-based models provide principles and guidelines for clinical practice, but ultimately, clinical decisions may be influenced most by a practitioner's epistemology (belief systems) and propensity for rational thinking.