In Naturales Questiones Seneca (ca. 4 BCE – 65 CE), the leading Stoic essayist and advisor to the Roman Emperor Nero, works to clarify the science—especially meteorology and physics—that underlies Stoic ethical and theological thought. The credo “follow Nature as a guide” was pervasive among Greek and Roman Stoic thinkers. But how should one do so when confronted by natural events that are counter-intuitive (mirrors, the size of the sun), downright terrifying (earthquakes, lightning), or simply puzzling (rainbows, comets)? Seneca considers the landscapes of the earth, what lies beneath the earth, and what lies above in the heavens. He surveys the views of earlier thinkers such as Aristotle and employs both observation and inferential reasoning (ratio), always with an eye toward the ethical implications for humans. He connects what exists in nature to how you and I should think and behave, often with a spirited critique of contemporary society, be it the luxurious habits of the rich or the misguided fears of the general public. He never loses sight of the idea that in studying the larger universe we acquire the proper perspective on the human world and its troubles and, ultimately, become closer to God, who is that universe. Seneca’s science is part of his philosophical self-fashioning. He uses ratio to explore not only the murky recesses of natural phenomena, but also the human soul.

These representative excerpts include Seneca’s treatment of various puzzling natural phenomena, his formulations of the tenets of Stoic physics, summaries of the opinions of earlier thinkers on specific questions (doxography or “history of doctrines”), and lively discussions of the moral and ethical issues that arise. It is my hope that this commentary will allow students at the intermediate level appreciate not only Roman science, but also Stoic philosophy. This work is a fascinating entry-point to both.

Readers of Lucretius’ De Rerum Natura will find many interesting points of similarity and contrast here with Lucretius’ Epicurean view of the natural world. While they disagree on the fundamentals of physics, both Lucretius and Seneca hope that the study of physics will lead to real ethical changes in their readers; and both works alternate between moving “purple” passages and explanatory, scientific sections.

Though he writes in prose, Seneca often quotes poets, especially Vergil and Ovid. The style, as in his other works, is engaging, artful, and lively. There are frequent addresses to the reader, rhetorical questions, many short, punchy sentences (sententiae), vivid imagery, and striking word order. Seneca often connects his account with previous works through quotations and intertextual references in order to sharpen his own views and put them into a productive dialogue with the poetry and philosophy of his predecessors. He also knits the work together with references to other passages in the Naturales Quaestiones itself (“intratexts”). These references and notable stylistic features will be pointed out in the commentary as they occur.

Apart from a few small changes in orthography and punctuation, the Latin text is that of Hine’s Teubner (1996a), except for the following modifications taken from the Budé text of Oltramare (1961):



















alia varia †fortitudine†

talia <fors> varia



loco peteret <***> ultimus cervicem

loco peteret ut ultimus cervicem


These are the selections:

  1. Book 3 pref. 1–4: Opening of the work as a whole.
  2. Book 3.15.1–8: Underground veins and arteries; the world/body analogy.
  3. Book 3.30.1–8: The end of the world and regeneration.
  4. Book 4a.2.12–15: A fight between crocodiles and dolphins in the Nile Delta.
  5. Book 4b.13.1–11: Critique of the trade of snow and the luxurious habits of the rich. 
  6. Book 5.13.1–15.4: How whirlwinds are created, and a digression about mining.
  7. Book 6.3.1–6.5.3: Earthquakes and the quest for knowledge.
  8. Book 6.8.1–6.10.2: Theories about the causes of earthquakes.
  9. Book 7.28.1–7.30.6: Conclusion of comet doxography and analysis of Aristotle’s view on comets.
  10. Book 1 pref. 5–13: The ethical value of the study of natural science.
  11. Book 1.13.1–14.6: Parhelia and other fires in the sky.
  12. Book 1.17.1-10: Mirrors and Roman decadence.
  13. Book 2.36–38: Fate, free will, and the efficacy of prayer.
  14. Book 2.59.1-13: Fear of lightning and consolation of death. The finale of the work.

The notes and vocabulary are meant to help intermediate Latin learners read the text smoothly. The vocabulary lists include all words not the in the DCC Latin Core Vocabulary. Latin words used in unusual senses are pointed out in the notes, often with links to the dictionary site Logeion. These links refer to the relevant section of the entry in Lewis and Short's Latin-English Lexicon (1879, abbreviated LS), which is digitized on Logeion. But there are other dictionaries there as well. In a few cases, notes refer to the fuller, more modern Oxford Latin Dictionary (OLD, 2nd ed. 2012, not available freely online) when that dictionary has the correct sense, but LS does not. Potentially tricky features are noted and linked to the relevant section Allen and Greenough’s Latin Grammar (abbreviated AG)

In addition to grammatical and lexical help, the notes cite parallel texts in Seneca and point out allusions to other authors. They discuss Stoic philosophical concepts, rhetorical devices, and the insights of notable scholars on Seneca’s thought. It is my hope that the notes will not only help to elucidate possible problems for students, but also inspire further interest in these topics. The NQ will appeal to Latin students interested in STEM fields, as well as those who enjoy epic poets such as Vergil and Ovid. This work is also an early example of the 2,000+ year tradition of scientific writing in Latin, a tradition which included writers such as Copernicus and Newton. For a collection of later Latin scientific writing suitable for introductory Latin students see Epstein and Spivak 2019.

Christopher Trinacty, Oberlin, Ohio, May 11, 2022


Cover image: a page from Astronomicum Caesareum (1540) by Michael Ostendorfer. Image Credit: Metropolitan Museum of Art. The most sumptuous of all Renaissance instructive manuals, this work explained the use of the astrolabe and other instruments used for computing planetary positions. The author, court astronomer to Emperor Charles V, also provided new observations on the comet of 1531 (Halley's Comet). 

Suggested Citation

Christopher Trinacty, Seneca: Natural Questions: Selections. Carlisle, Pennsylvania: Dickinson College Commentaries, 2022. ISBN: 978-1-947822-18-4