This book changed my entire worldview. Anyone who’s ever felt left out of history class by the prevalence of masculine pronouns has been waiting for Blood, Bread, and Roses. Grahn, celebrated feminist poet and writer, approaches anthropology from humanity’s very inception with the perspective that menstruation was the mother of invention. She argues that menstrual seclusion rituals, widespread among early societies, established human understanding of separation and synchronicity, and that they conveyed that understanding through metaform, behavior that communicates social mores and shared belief. Scholarly, but readable and stimulating, Grahn draws from prehistoric and modern cultural comparison, etymology, and poetic inference to detail the roots of religion, law, mythology, mathematics, science, clothing and eating. While readers may not agree with all her theories, the book is indispensable for anyone who has wondered about the other half of historical gender bias, and longed for more balanced alternate theories. ( )