Shonna Days's recent column ("Faith, science may help to heal depression," Oct. 8) shows that she doesn't understand how science works. For scientists to advance their understanding, they must discard mysticism and replace it with skepticism. In other words, mysticism is the antithesis of science.

If we relied on religious dogma rather than healthy investigation of phenomena without preconceived notions, then we would still believe that we live in a Earth-centered solar system. Human society would be without modern medicine and the microelectronic devices that we use every day, because according to mystical dogma, all of these discoveries should have been impossible.

Ms. Days also attacks evolution as "doctrine," a common argument among creationists. Personal opinions about creationism aside, it's improper to characterize a scientific theory as doctrine. The theory of macroevolution is the best nonmystical explanation that currently exists to explain the evidence available.

If evidence emerges to disprove the theory, biologists will discard it and develop a new one that considers the new information available. There exists no devotion to evolution as a doctrine.

That's how we scientists work -- we only accept propositions that are directly supported by evidence available for observation. Ms. Days, as a nonscientist, doesn't understand this and therefore is unable to comment intelligently about how science works.