The next books (4A, on the Nile, and 4B, on clouds, rain, hail, and snow) are concerned again with favorite Senecan themes and again are deeply relevant to his own current life: the topics are escapism and retirement, and, again, the corruptions of luxury (since the excessive consumption of snow and ice is a classic instance of excessively demanding elite tastes). Book 5, on the winds, is concerned with freedom and with the proper reach of empire, since the topic allows Seneca to examine the classic question of whether it is a good thing for the winds to have carried naval and merchant ships from one corner of the world to another for conquest and trade. We learn that it was not nature but greed that made humans act in this way: “it was not enough for us to be crazy in our own part of the world!” Book 6 takes us to earthquakes, a topic that Seneca tells us he already wrote about in his youth. It allows him to return to his preoccupation with fear and freedom: there is nothing more terrifying than the rumble of an earthquake, but knowledge of its causes allows us to surmount these fears and face death bravely—than which there is nothing more important (NQ 6.32.5). Book 7, on comets, allows for a discussion of the limits of human knowledge, and the power of the gods, who “have not made everything for humans.” This topic again has a strong political dimension, since comets were supposed to portend the destinies of kings and emperors, and a famous comet was seen “in the very happy principate of Nero” for six months, moving in the opposite direction from a comet associated with Claudius (7.21.3). While apparently trotting out the standard Neronian line here, Seneca manages also to suggest that it is mere narcissism for an emperor to think a comet has anything to do with himself. Nero’s comet was lured with the desire for “food,” just like fire, which follows where it has fuel to feed on, not motivated by a need to respect the young leader. The Natural Questions thus implies that Nero, too, would benefit from taking a view from above.
The last two books in order of composition are the most intensely focused on questions of human life in general, and Seneca’s in particular—while at the same time taking on a vast canvas of the natural world. Book 1 (the penultimate book composed) discusses rainbows, meteors, and other lights in the sky, but it is ultimately about human self-knowledge, self-deception, and desire. The rainbow, Seneca argues, is created by the reflections of innumerable raindrops, which create mirrors; the same is true, mutatis mutandis, of clouds. All these natural mirrors create various kinds of optical illusions, since rainbows, for example, have no real substance but look like a great arc in the sky: “what is shown in the mirror does not exist” (NQ 1.15.7).
This leads to an extensive discussion of somebody called Hostius Quadra, a rich man obsessed with sex, who was eventually killed by his slaves in revenge for the degradations he had put them through. Hostius, Seneca tells us, enjoyed having group sex with both men and women and also set up mirrors all around while he was in the act, which would exaggerate the size of his male partners’ genitalia. He used mirrors to increase his corrupt desires and failed to realize that nature gave us mirrors “so that a human being can know himself.”7 Hostius, in his obsession with watching himself (and especially with watching himself being penetrated) can be seen as the opposite of Seneca, in his idealized literary persona. Seneca maintains firm and vast boundaries around himself, making both body and soul impenetrable; and he looks for a mirror to reflect his own life, not in the luxurious mirrors created for the perversities of elite Roman life but in the clouds and raindrops of the divine sky.
Seneca presents his studies in physics as giving meaning to his life and allowing him a perspective that goes beyond the confines of his own body: “If I had not been allowed access to these fields, it would not have been worth it to be born. What reason could I have to be happy for being admitted to the number of the living? Just to eat and drink?” (NQ 1. Pref. 4). This sentiment is a variation on the philosophical trope that is most vividly expressed by Plato’s Socrates in the Apology: “the unexamined life is not worth living by a human being.” The Platonic line suggests that human beings ought to devote their lives to the study of ethics: a human being should spend his or her life in self-examination. But in Seneca’s version, there is a striking shift of emphasis away from a human behavior toward the study of the vast universe of nature: “Ah, how despicable humans are, unless we rise above the human!” (NQ 1. Pref. 5). Seneca draws a sharp contrast between the kind of philosophy that deals with man—moral philosophy—and the “loftier, more intellectual” kind, which deals with the gods and the works of heaven, which “leads us up out of darkness, to source of shining light.” The mystical language suggests that the study of physics can provide a refuge or sanctuary far from the taint and sickness of human affairs. The study of science is not, for Seneca, motivated by merely practical considerations; it is a source of spiritual regeneration and redemption.
In the Natural Questions, Seneca worked to turn his attention away from the anxieties of political, human life toward the broader, vaster view of natural phenomena. He implies that his addressee, Lucilius, can escape not only from the evils of the external human world but also from himself by releasing his mind to the study of the heavens, which is the ultimate form of liberation. This, we are told, “unchains the mind, prepares it for the contemplation of heavenly things, and makes it worthy to associate with God” (NQ 1. Pref. 6).
But we could also see it as an attempt to put his personal, political, and moral struggles into a larger perspective. Seneca expands a theme popular among Roman Stoics: that there is a distinction to be drawn between the small state or city in which an individual may live (such as Carthage, or Rome: these are examples of the lesser republic, the republica minor) and the large community of which we are all a part. Seneca’s shift toward the big picture is an acknowledgment of a larger reality, a world of which his life is one small part.