 The Manuductio starts with a history of the most important philosophical schools which existed in antiquity, followed by a discussion of the origin and succession of the various Stoic schools, their different views on the definition and parts of philosophy. He then comes to the Stoic conception of the truly wise man. Taking his cue from Aristotle (Metaphysics 982a), Lipsius asserts that the main characteristic of the wise man is that “he knows in a sense all the instances that fall under the universal” (Manuductio II.8). The wise man (sapiens) — whom, following the Greek Stoic Panaetius, Lipsius regarded as in a state of progress (proficiens) — will therefore study the physical phenomena and their causes, learning the laws of nature and their relationship to the rules of conduct in order to discover the nature of good and evil. If ethical precepts are to lead to wisdom, they must be reinforced by general doctrines and moral training. Contrary to the Stoic belief that both God and nature need to be comprehended by the use of reason, Lipsius — embracing here a Platonic epistemology more in line with Christianity — saw the understanding of God and his works as a divine gift (Manuductio II.10). The road to wisdom, however, can only be discovered by following the rules of conduct laid down by nature. This truth must be deduced by reasoning, which explains Lipsius’s elaborate account of the Stoic theory of knowledge. Both philosophical doctrines and moral precepts are necessary and complementary to one another for an appreciation of the virtues and as guides to the good life. Without a Stoic understanding of the world and of the supreme good (summum bonum), life cannot be lived happily. According to Lipsius (who quotes Seneca’s De vita beata), living happily is the same as living according to nature (Manuductio II.15).