In this chapter weâve seen that the most obvious sources of credibilityâexternal validation and statisticsâ arenât always the best. A few vivid details might be more persuasive than a barrage of statistics. An anti-authority might work better than an authority. A single story that passes the Sinatra Test might overcome a mountain of skepticism. Itâs inspirational to know that a medical genius like Marshall had to climb over the same hurdles with his idea as weâll have to climb with oursâand to see that he eventually prevailed, to the benefit of us all.