As I review the galleys for R. Elijah J. Schochet's biography of the Bach, Rabbi Joel Sirkes: His Life, Works and Times (Expanded Edition) (should be in stores before the High Holidays), I came across the following interesting passage on page 50:
Religion was in many respects a simple matter for Joel Sirkes. His problems of philosophy and faith were few, if any at all. Rabbi Joel was a determined antagonist of all philosophic study, equating it with heresy. He regarded faith in the existence of God as an obvious self-evident truth, apparent to anyone by the power of logic as well as the testimony of tradition.