Near the end of “On Earthquakes” in Natural Questions, Seneca turns to why this study is important and necessary. (This is not the first time he does so or will do so.) In so doing, he re-establishes a pattern that he enacts throughout NQ:

1. provoke the reader through literary representation of awe, marvel and wonder at the forces of nature;

2. turn to rational explanations for this awe as an indicator of the presence of “natural laws”;

3. then explain the moral and ethical importance of consistently reactivating the first two steps of the pattern.

For Seneca, this is how philosophy works. At the beginning of “On Fires,” he describes this explicitly. The point is that the two “branches of philosophy” work together. To wonder at the power of nature and to see that power as the working of natural laws is to see oneself in a proper perspective. You’ll laugh at the “paved floors of the wealthy”; the boundaries between empires and tribes will seem “ridiculous”; you will see the world as a “mere pinprick on which you sail.”

To look into all of this, to learn about it, to brood over it—is that not to transcend one’s mortality and to be registered with a higher status? “What use will that be to you?” you say. If nothing else, at least this: I shall know that everything is puny when I have measured god.” (Preface 17)

Working together, the two branches of philosophy — knowledge of nature (physics) and knowing how to act (ethics) — are a means of fashioning of oneself out of the events of life. But let’s not get ahead of ourselves just yet.

First, like Lucilius, we must come to grips with “death”, which is the necessary and ultimate realization that comes from seeing the world and oneself as a “mere pinprick.” Engaging with nature and understanding the power manifested in its sublimity is ultimately to confront one’s own death and its inevitability. For the Stoic, death is the ultimate “fortune” that you cannot control.

It is at the end of “On Earthquakes” — where this pattern of marvel, explanation and ethical self-reflection is most clearly established by Seneca. Here Lucilius is exhorted to rehearse his own death:

Let us imprint this on our minds, let us constantly say this to ourselves: “We must die.” When? What does that matter to you? Death is a law of nature; death is the duty and tribute of mortals, and the remedy for every suffering. Anyone who is afraid is longing for it. Forget everything else, Lucilius, and concentrate on this one thing, on not being afraid of the word “death.” By constant reflection make death a friend of yours, so that, if it allows, you can go out to meet it. (“On Earthquakes” 32.12)

“Constantly saying to ourselves,” “imprinting on the mind,” “concentration,” “constant reflection” on the inevitability of death — death as the irrevocable condition of being human — are philosophical techniques that bind the two branches of philosophy. In the process, a self is fashioned.

Echoing Foucault, if there is an interiority here, it is not original — rather it is an effect, an outcome of self-talk and “constant reflection.” Elsewhere, Seneca will write about these techniques as “sinking in”, “absorbing”, “planting seeds” and other metaphors that bind the techniques to the effects. Take, for instance, the very short Letter 38 where he describes the desired effects of words, philosophy and reason using these metaphors:

I say it again: words work like seeds. Though tiny, they achieve much. Only, as I said, the mind that receives them has to be suited to them, and has to absorb them. Then it will reproduce them, the many more than it received. (Letters 38.2)

There is no pre-existing interiority here. There is a movement described as absorption, but in the crossing of the boundary, the absorbing side must be prepared — “it has to be suited” and ready. The soil exists, but the hole has to be dug out and prepared.

In NQ, this sinking in is also a tapping into, which is most forcefully described in the first part of “On Fires” where the two branches of philosophy are both discussed and enacted. The tapping into passage is worth quoting at length:

Up above there are vast spaces, which the mind is allowed to enter and occupy, provided it takes scarcely anything of the body with it, that it wipes away any uncleanness, and that it soars upward, unencumbered, nimble and self-reliant. When it has reached those regions, it finds nourishment, it grows, and, as though freed from its chains, it returns to its origin. It has the proof of its own divinity, that it takes delight in the divine and enjoys it not as someone else’s possession but as its own. For confidently it watches the settings and resigns of the stars, and their differing but harmonious paths; it observes where each star reveals its light to earth, where its zenith is, to what point it descends. As a fascinated spectator, it examines and inquires into each detail. And why should it not inquire? It knows this all relates to itself. (“On Fires” Preface 11-13)

From our modern (post-Freudian, Christian-infused) vantage point, it is easy to read “return to its origin” as accessing an already-existing interiority, but that would be to ignore all that has come before. It would risk making Seneca into a proto-psychologist well ahead of his time. Seneca’s world is a collection of forces — earth, air, water, fire — all animated by “breath”. The breath that causes earthquakes is the very same breath that causes agitation in the body. Everything exists on the same plane and is subject to the same forces of nature. It is a self-contained system. From this perspective, it is better to say that these forces are running through you rather than inside you.

So too with “reason.” To exercise reason is to tap into the divine, to tap into the very same force running through the human and the divine. In Seneca we find no primal forces that are embedded in a uniquely human unconscious. Yes, there are “impressions”, but they certainly do not have their own motivations. They receive external stimuli and initiate the first “movement” to a response. The response — the “impulse” and the “assent” (see Letter 113) — are the subsequent “movements” and are the product of “habits” implanted in us from the culture in which we live. In other words, “impressions” don’t provide any motivation for the ensuing action. They just provoke the next steps in a mechanized process. Motivation comes from the habits we have — good and bad. The individual is always a product of its culture.

What you find in Seneca are not individuals that overcome nature through reason. Rather, you find individuals who must constantly self-talk, constantly review and correct their behavior. (Foucault pointed out that Seneca’s language of the self is more administrative that juridical and punitive.) Seneca’s proficiens are not struggling with the natural impulses of an unconscious — Civilization and Its Discontents would make no sense for Seneca, though talk therapy certainly would.

Rather, the proficiens are overcoming bad habits; they are deconstructing themselves to remake themselves with new habits founded on the ability to step back from the heat of the moment and exercise good judgment so as to act virtuously in any given situation.

What is virtue? True and unshakable judgment, for from this come the impulses of the mind; by this, every impression that stimulates impulse is rendered perfectly clear. (Letter 71.32)