 The most reliable guide for human inquiry, he argues, is mankind’s natural propensity toward what is good and true. This light of our mind, as he also calls it, is always, directly or indirectly, inclined toward what is good and true, and can be regarded as the beginning and origin of prudence and of all sciences and arts. This natural propensity can be perfected if it is subjected to teaching and exercise, just as the seeds of plants grow better if they are cultivated by the industrious hands of a farmer. He found philosophical grounds for this idea in Cicero’s report (see, e.g., De natura deorum (On the Nature of the Gods), I.43–5) of the Hellenistic theory of anticipationes (anticipations) and of naturales informationes (natural notions), which we have not learned from teachers or custom, but are instead derived and received from nature (III, 356–7). The topics, which Vives conceives as a reflection of the ontological order, represent another valuable instrument for human inquiry. In his view, the topics are a set of universal aspects of things that help to bring order to the great variety of nature. As such, they play an important role as organizing principles of knowledge. They are like a grid through which knowledge can be acquired and arguments formulated (see Nauta, 2015). Nevertheless, human knowledge can be nothing other than a finite participation in creation. Because of the limitations that characterize man’s fallen state, investigations into the realm of nature can only lead to conjectures, and not to firm and indubitable knowledge, which we neither deserve nor need. In De prima philosophia, Vives writes: “human inquiry comes to conjectural conclusions, for we do not deserve certain knowledge (scientia), stained by sin as we are and hence burdened with the great weight of the body; nor do we need it, for we see that man is ordained lord and master of everything in the sublunary world” (III, 188). In his opinion, certainty is not a prerequisite for advances in science and philosophy; and as a criterion for scientific progress and for the rational conduct of life, he advocates a method consisting in sound judgment based on experience.