In his critically-acclaimed biography, Worldly Philosopher: The Odyssey of Albert O. Hirschman, Jeremy Adelman, writes that Hirschman was greatly influenced by Italian intellectual Eugenio Colorni, who viewed doubt as an essential and very positive part of the creative process:

Colorni believed that doubt was creative because it allowed for alternative ways to see the world, and seeing alternatives could steer people out of intractable circles and self-feeding despondency. Doubt, in fact, could motivate: freedom from ideological constraints opened up political strategies, and accepting the limits of what one could know liberated agents from their dependence on the belief that one had to know everything before acting, that conviction was a precondition for action.

If we apply Colorni’s thinking to Mick Stevens New Yorker Cartoon The Private Doubts of Christopher Columbus …

accepting the limits of what he could know liberated Columbus from his dependence on the belief that he had to know everything before acting

The very counter-intuitive views of Hirschman and Colorni turn commonly accepted ideas of productivity on their head. Stumbling and doubt are a big part of making ANYTHING.