Could simply imagining positive interactions promote tolerance between different social groups? This imagined contact hypothesis (Crisp & Turner, 2009) is just one example of a range of psychological interventions that capitalize on people's capacity for mental simulation. The approach is controversial, perhaps because imagery appears somewhat insubstantial when set against the visceral realities of war, deep-rooted prejudices, or extreme acts of genocide. We counter that mental simulation is an essential element of the human experience and, as such, a correspondingly critical component of behavioral change strategies. This argument is supported by considering imagery's central role in advances spanning the breadth of psychological science-from studies of the biological correlates of motor control, mimicry, and theory of mind to the cognitions and emotions that characterize reasoning, self-regulation, planning, and goal pursuit. Mental simulation is not merely a proxy for real experience: It is a critical cognition that precedes and precipitates the full spectrum of human behavior. Thus, while imagery techniques may appear trivial next to pervasive problems like prejudice, this should not distract us from the power and potential they offer as tools for transforming social policy.