Following Mr. Bixby and some other 19th century scientist-philosophers such as Claude Bernard, relevant scientific actions should, as a matter of primary importance, be explained with reference to the competence and not to the intentions of those involved. The background is a reliabilist virtue approach - a widespread tendency in 19th century epistemology and philosophy of science. Bixby's approach includes a critique of some constructivist arguments and establishes a mutually supportive connection to conceptions of scientific progress.