Husserl and Frege did not criticize psychologism on the ground that it deduced the norms of logic from non-normative premises (naturalistic fallacy), as is often supposed. Rather, their refutation of psychologism assumes that such a deduction is possible. Husserl compared the rules of logic to those of technology, on the supposition that they have a purely theoretical basis. This conception of logic is critically examined, and it is argued (contra Follesdal) that Frege held a similar view.