ABSTRACT
Throughout this book, I use the terms joy and mirth to denote the positive message that smiles and laughter communicate. This is not uncontroversial. In previous work, for example, I labeled this message more generically—as an idea of positivity. My unwillingness then to settle on a definition, as with my willingness now to act as though I have actually reached one, is motivated by factors as mundane as they are essential. After all, definitions are just preliminary sketches. They may aid us to fill in the tableau, but only experience is capable of making the picture clear.
