 Despite his fame as a philosopher of purely metaphysical problems, such as the relation of the soul and body, or God’s existence, it would not be incorrect to conclude that Descartes was a scientist first and a philosopher second. Not only did Descartes’ interest and work in science extend throughout his entire scholarly career, but some of his most important metaphysical works (e.g., the Meditations) were prompted by a perceived need to equip his science with a metaphysical foundation that would be acceptable to the Aristotelian-influenced Scholastics. Yet, one must be careful not to impose modern conceptions on the “natural philosophy” of earlier centuries, for much seventeenth century science was practically indistinguishable from the more speculative metaphysics of the era (and thus the label “natural philosophy” is particularly apt for describing seventeenth century science). In fact, much of Descartes’ science is only part of a much larger system that embraces all areas of philosophical investigation, including both his physics and metaphysics.