In this wide-ranging and thought-provoking study, Maryanne Cline Horowitz explores the image and idea of the human mind as a garden: under the proper educational cultivation, the mind may nourish seeds of virtue and knowledge into the full flowering of human wisdom. This copiously illustrated investigation begins by examining the intellectual world of the Stoics, who originated the phrases "seeds of virtue" and "seeds of knowledge." Tracing the interrelated history of the Stoic cluster of epistemological images for natural law within humanity--reason, common notions, sparks, and seeds--Horowitz presents the distinctive versions within the competing movements of Hellenistic Judaism and early Christianity, Augustinian and Thomist theologies, Christian mysticism and Kabbalah, and Erasmian Catholicism and the Lutheran Reformation. She demonstrates how the Ciceronian and Senecan analogies between horticulture and culture--basic to Italian Renaissance humanists, artists, and neo- Platonists--influence the emergence of emblems and essays among participants in the Northern Renaissance neo-Stoic movement. The Stoic metaphor is still visible today in ecumenical movements that use vegetative language to encourage the growth of shared values and to promote civic virtues: organizations disseminate information on nipping bad habits in the bud and on turning a new leaf. The author's evidence of illustrated pages from medieval, Renaissance, and Enlightenment texts will stimulate contemporary readers to evaluate her discovery of "the premodern scientific paradigm that the mind develops like a plant."