Doubt causes us to hold a strong position a bit more loosely, such that an acknowledgment of ignorance or error doesn’t crush our sense of self or leave us totally unmoored if our position proves untenable. Certainty is the opposite: it hampers inquiry and hinders growth. It teaches us to ignore evidence that contradicts our ideas, and encourages us to defend our position at all costs, even as it reveals itself as indefensible. Certainty sees compromise as weak, hypocritical, evil, suppressing empathy and allowing us to justify inflicting horrible pain on others.
