Also, even if technocrats provide reasonable estimates of a risk, which itself is an iffy enterprise, they cannot dictate what level of risk people ought to accept. People might object to a nuclear power plant that has a minuscule risk of a meltdown not because they overestimate the risk, but because they feel that the cost of a catastrophe, no matter how remote, are too dreadful. And of course any of these trade-offs may be unacceptable if people perceive that the benefits would go to the wealthy and powerful while they themselves absorb the risks. Nonetheless, understanding the difference between our best science and our ancient ways of thinking can only make our individual and collective decisions better informed. It can help scientists and journalists explain a new technology in the face of the most common misunderstandings. And it can help all of us understand the technology so that we can accept or reject it on grounds that we can justify to ourselves and to others.