This book discusses the Aristotelian setting of Thomas Hobbes' main work on natural philosophy, "De Corpore" (1655). Leijenhorst's study puts particular emphasis on the second part of the work, entitled "Philosophia Prima," Although Hobbes presents his mechanistic philosophy of nature as an outright replacement of Aristotelian physics, he continued to use the vocabulary and arguments of sixteenth and seventeenth-century Aristotelianism. Leijenhorst shows that while in some cases this common vocabulary hides profound conceptual innovations, in other cases Hobbes' self-proclaimed "new" philosophy is simply old wine in new sacks. Leijenhorst's book substantially enriches our insight in the complexity of the rise of modern philosophy and the way it struggled with the Aristotelian heritage.