One night last fall I lay awake wondering how I should begin this essay. I imagined a variety of ways I could write the first sentence and the next and the one after that. Then I thought about how I could tie those sentences to the following paragraph and the rest of the article. The pros and cons of each of those options circled back and forth in my head, keeping me from drifting off to sleep. As this was happening, neurons were buzzing away in my brain. Indeed, that neural activity explains why I imagined these options, and it explains why I am writing these very words. It also explains why I have free will.