Doubt becomes dangerous when you mistake uncertainty for evidence.

Not knowing whether something will work is simply the normal condition of anything worth attempting. The mistake is treating that blank space as if it were a finding, as if the absence of certainty were a report that the answer is no. Doubt is a question, and questions do not contain their own answers. Once you start reading it as proof, you stop testing anything.

When you feel hesitant, ask what you actually know versus what you merely have not established yet. Keep those two lists separate on purpose. Then design the smallest possible test that would move something from the second list to the first.