Do we have free will? Is there meaning to life? A slew of new books provide some insights into how scientists are supplementing Plato with PET scans, hoping to answer these questions.

In My Brain Made Me Do It: The Rise of Neuroscience and the Threat to Moral Responsibility (Prometheus Books, 2010), Eliezer J. Sternberg examines studies that pinpoint areas of the brain associated with exercising free will and suggests that our ability to decide makes us largely responsible for our actions.

Although we can easily spot and describe the features that make someone wise, defining wisdom is more elusive. In the new book Wisdom: From Philosophy to Neuroscience (Knopf, 2010), journalist Stephen S. Hall discusses studies that show brain activity corresponding to wise traits, such as moral judgment.

In The Brain and the Meaning of Life (Princeton University Press, 2010), philosopher and psychologist Paul Thagard discusses the reason we are wired to form social bonds: loving relationships can give a sense of purpose to our lives.