This is a great book. While the subtitle and structure resemble that of a dictionary, it is a rather a summary of concepts in broader anarchist thought, so rather than a strict definition, it is more of a discussion of how a given concept has appeared and been approached in anarchism. Love, friendship, power and violence are just some of the concepts explored. The author makes an interesting balance between the individualistic and collectivist branches of anarchism showing them as not being inherently opposed to each other. I would primarily recommend to someone wanting to be familiar with anarchist theory as it is clear and didactic enough for that purpose, but a more experienced person will still find enjoyment reading the book.