Adam Smith’s Space Odyssey

history of astronomy just sentiments

Erik W. Matson for AdamSmithWorks
Rendered illustration of Newton's Rotative Reflector Telescope

Adam Smith's “An Inquiry into the Principles which Lead and Direct Philosophical Enquiries; Illustrated by the History of Astronomy.” is an adventure into reflection on the passional and aesthetic dimensions of scientific and philosophic practice.

"As we participate in Smith’s passions, we can’t help but feel still higher levels of surprise, wonder, and admiration: surprise at the ending of Smith’s essay, wonder at the novelty of his ironic self-contradiction, and admiration for his genius. The sentiments encourage us to puzzle over Smith’s contrariety and arrive at a fuller sense of the purpose of his essay."

November 23, 2022
Smith developed an essay over the course of his career, published posthumously, now commonly abbreviated as “History of Astronomy” (HA). The abbreviated title facilitates a misapprehension. The history of astronomy is, in some sense, auxiliary; it is a vehicle with which Smith develops ideas about the nature of the scientific or philosophic enterprise itself. The essay’s full title makes this clear: “An Inquiry into the Principles which Lead and Direct Philosophical Enquiries; Illustrated by the History of Astronomy.”
HA, we find, is an adventure into reflection on the passional and aesthetic dimensions of scientific and philosophic practice. The essay teaches us something important about Smith’s rhetorical method and his ideas of the deeply personal nature of knowledge.
Teaching by showing
Donald Livingston describes David Hume as an essentially dialectical thinker. By this he means that for Hume, “philosophical insight is gained by working through the contrarieties of thought which structure a drama of inquiry” (Livingston 1984, 35). This description of Hume’s method can be used to characterize important moments in Smith’s work. One such moment is the parable in the Theory of Moral Sentiments of “the poor man’s son” (Smith 1982b [hereater 'TMS'], 181). The poor man’s son sets out with wrongheaded ambitions that lead him to effectively pursue his own unhappiness. But his actions, Smith contends, have unintended beneficial consequences for humankind, leading him and his trading partners to “cultivate the ground, to build houses, to found cities and commonwealths, and to invent and improve all the arts and sciences” (TMS, 183). In the juxtaposition of these perspectives, which culminate in the first published “invisible hand” passage in Smith’s work, Smith, as I’ve argued elsewhere, “actively encourages the reader to reflect upon how the pursuits of wealth and happiness [can be] balanced and complementary, not oppositional modes of life” (Matson 2021, 834). Smith works to convey something about the relationship between commercial pursuits and the good life, in other words, not simply through explication, but by drawing the reader into a progression of sentiment.
This rhetorical method of teaching by showing looms large in Smith’s ethics. As Charles Griswold puts the point, in TMS Smith “focuses our attention on particulars and experience and attempts to get us to ‘see’ things in a certain light rather than simply to argue us into accepting a philosophical position” (Griswold 1999, 829). We learn the look and feel of proper moral judgment by observing the enactment of moral judgment throughout Smith’s prose. A similar rhetorical method is essential to the dramatic arc of “History of Astronomy.” HA attempts to teach us something about the personal dimensions of knowledge and the sentimental nature of the scientific process not simply by explanation, but by ostension—that is, by showing the process. Smith offers the reader a drama, a progression of sentiment.
Passion for regularity
HA begins with a treatment of three sentiments that give rise to philosophy: wonder, surprise, and admiration, characterized as follows. “We wonder at all extraordinary and uncommon objects”; “we are surprised at those things which we have seen often, but which we least of all expect to meet with in the place where we find them”; and “we admire the beauty of a plain or the greatness of a mountain” (Smith 1982a [hereafter 'EPS'], 33). Underneath these sentiments lies a natural belief, one that all human beings instinctively accept, and which must be taken for granted in all our reasonings. This belief is the assumption that reality proceeds uniformly in accordance with rules.
Smith seems to follow Hume in admitting that we have no way to demonstrate that reality is in fact regular and uniform (Matson 2019). Our natural belief in causal relations, and even in the enduring existence of the objects of sensory experience, is vulnerable to skeptical criticism. But our passion for coherence, our conviction that irregularities could be accounted for with fuller accounts of reality, wins the day over skeptical pause. Hume writes, “thus the sceptic still continues to reason and believe, even tho’ he asserts, that he cannot defend his reason by reason” (Hume 2007, 125). The mind displays a deep commitment to the idea of regularity; skepticism is rendered ineffectual not by ratiocination, but by the natural strength of our conviction that the world makes some kind of sense, even if we lack sufficient knowledge to participate in the apprehension of that sense.
Within our natural belief in regularity, philosophy, Smith tells us, is essentially an effort of imagination to impose the greatest possible degree of order and coherence upon the chaos of experience. We experiment with various interpretations to render the “theatre of nature a more coherent, and therefore a more magnificent spectacle, than it otherwise would appear” (EPS, 46). We are temporarily jarred out of our current interpretative framework by the sentiment of surprise, caused by unexpected observations and experiences. If we cannot find a way to accommodate such surprises by “enlarg[ing] the precincts” (EPS, 40) of our framework, we feel wonder. And wonder, Smith says, impels us to reimagine the way things are and to engage in a process of generating new modes of explanation—potentially bringing discovery.
Although it receives in HA much less explicit attention than surprise and wonder (both have dedicated subsections in the essay), admiration enters the philosophic process at various points. Two are worth mentioning here. First, admiration affects how the knowledge-seeker allocates his attention, guiding him towards grand and beautiful objects, such as the celestial heavens or the breathtaking concatenation of human activities comprising the modern economy. Second, admiration recommends to him remarkable men and women worthy of emulation in his ponderings, like Isaac Newton. In TMS, Smith writes, “it is the great leader in science and taste, the man who directs and conducts our own sentiments…who excites our admiration, and seems to deserve our applause” (TMS, 20). Admiration inspires the effort to understand and enter into great minds; that effort is an essential part of the cultivation of intellect and the practice of philosophy.
HA as drama of inquiry
After surprise, wonder, and admiration, astronomy appears on the scene. The history of astronomy is framed as a case study in the role of the intellectual passions in the scientific process. In transitioning to this case study, Smith makes an important caveat. He tells the reader that he intends to treat systems of astronomy not as explanations of reality, but as inventions of the imagination to satisfy the mind’s desire for order and tranquility (EPS, 46). This statement of intent is the first key moment in HA’s drama of inquiry.
In the earlier part of his account of the history of astronomy, treating the progression from Aristotelean to Ptolemaic to Cartesian astronomy, Smith emphasizes—in keeping with his stated intentions—the passional, aesthetic, and sociological aspects of what those thinkers said, rather than emphasizing their theorizing as better or worse approximations of reality. Such systems are treated as in or out of “vogue” (EPS, 63), as relieving the imagination from embarrassment (EPS, 62), and advancing on the basis of “beauty and simplicity” (EPS, 75).
As the essay unfolds, however, Smith appears to have trouble keeping his distance from the ambition to know reality. He slips towards the common treatment of scientific explanations not just as systems fitted to sooth the mind, but as attempts to describe reality. The slippage becomes pronounced in his treatment of Newton.
In the final paragraph of the essay, Smith abruptly takes notice of the progression within his own thinking. He realizes his departure from his announced plan. He has failed to treat theories of astronomy merely as efforts to render the theater of nature agreeable and coherent. He has been led—unavoidably, it seems—to view Newton’s system not just as the latest, most agreeable system, but as an explanation of the world as it actually is. He explicitly calls attention to his failure, such as it is, in the final words of the essay:
And even we, while we have been endeavouring to represent all philosophical systems as mere inventions of the imagination, to connect together the otherwise disjointed and discordant phaenomena of nature, have insensibly been drawn in, to make use of language expressing the connecting principles of this one, as if they were the real chains which Nature makes use of to bind together her several operations. Can we wonder then, that [Newton’s system] should have gained the general and complete approbation of mankind, and that it should now be considered, not as an attempt to connect in the imagination the phaenomena of the Heavens, but as the greatest discovery that ever was made by man, the discovery of an immense chain of the most important and sublime truths, all closely connected together, by one capital fact, of the reality of which we have daily experience. (EPS, 105)
This delightful passage marks the second key moment in HA’s drama of inquiry. Smith praises the principle of gravity, “one capital fact, of the reality of which we have daily experience,” that made possible Newton’s integration of the sublunar and the heavenly. He simultaneously intimates a second “capital fact,” which is the true discovery of his odyssey: the mind can’t escape its ambition to know and explain reality, and to view its deepest theories as truth.
Pondering Smith’s contrariety 
The two key moments of Smith’s drama together make a contrariety, which we can now express with the following propositions:
  1. Philosophical systems can be treated as inventions of the imagination, fitted to sooth the human passion for regularity and coherence. (EPS, 46)
  2. We cannot avoid but treat the philosophical systems to which we adhere as real accounts of the workings of the universe. (EPS, 105)
Smith invites us to ponder the contrariety. He does so by expressing—and thus invoking in us, his sympathetic readers—the three sentiments he described earlier as giving rise to philosophy. We feel surprised upon observing Smith’s surprise at his subconscious slide towards realism. We wonder as Smith wonders at the power and beauty of Newton’s philosophy. And we admire with Smith the singularity of Newton’s genius.
As we participate in Smith’s passions, we can’t help but feel still higher levels of surprise, wonder, and admiration: surprise at the ending of Smith’s essay, wonder at the novelty of his ironic self-contradiction, and admiration for his genius. The sentiments encourage us to puzzle over Smith’s contrariety and arrive at a fuller sense of the purpose of his essay.
What are we to make, then, of the contrariety? In Matson (2019) I suggested that Smith intends HA to be something like a rhetorical exercise in Humean naturalism. In developing the sentimental and aesthetic aspects of inquiry, Smith admits that our natural beliefs in causal relations and the existence of objects outside of our field of sensory experience are unverifiable through reason alone, and, from that observation, skepticism can ensue. But, if our idea of what we call causation derives from repeated association of objects (see EPS, 40-41), what knowledge can we have of true causal relations? Such skepticism is unstable, however, and Smith illustrates its instability through his own personal progress of sentiment throughout HA. Smith shows the reader the process by which the mind naturally gravitates towards belief formation by going through the process himself. In showing how he is unable to keep to his intent of treating all scientific systems with a degree of distance, Smith intimates something about the psychological robustness of our beliefs in our own explanations.
In 2019, I characterized the overarching message of HA in this way: “if unverifiable belief dominates an investigation into the very principles directing scientific or philosophical inquiry, then such unverifiable belief should be understood to subconsciously constitute science more generally” (Matson 2019, 266). I now think this characterization somewhat misses the mark. The phrase “unverifiable belief” misconstrues the main point I believe Smith seeks to convey. Smith is not agnostic on the truth-value of various scientific systems, which some parts of Matson (2019) seem to suggest. The larger point, I believe, is that Smith sees that truth is not received passively, but engaged with, actively and personally, and that such engagement requires commitment, in something like the sense of that concept advanced by Michael Polanyi (1962).
Commitment amounts to “the affirmation of personal convictions with universal intent” (Polanyi 1962, 341). Only from within a personal commitment can we comment on the truth or untruth of a philosophical interpretation. I now think that it is something along these lines that Smith’s drama of inquiry looks to convey. Even in the face of our admission of room for potential future improvement, even in the face of our own reflections on the sociological and aesthetic dimensions of scientific and philosophical practice, we can’t help but profess our convictions of truth, based on our deepest-to-date modes of understanding. Even in the face of his extensive consideration of the passional and social elements of the scientific process, Smith, apparently, can’t help but treat Newton as exceptional, as the standard by which truthfulness of a system of astronomy is to be measured.
Smith calls attention to his own commitments and the way they’ve shaped his assessment of the history of astronomy, despite his apparent intentions. In so doing, he intimates something to the reader about his views on the irreducibly personal and passional nature of inquiry. To rephrase my 2019 characterization, then: if personal commitment dominates an investigation into the very principles directing scientific or philosophical inquiry, then such commitment should be understood to pervade scientific and philosophical practice generally. HA does not convey an anti-realist attitude about the truth-value of scientific explanations; rather, it conveys a passional, sentimental conception of scientific practice, along with a personal conception of how one apprehends truth itself.

Erik Matson is a senior research fellow at the Mercatus Center at George Mason University and the deputy director of the GMU Adam Smith program. His personal website is

This essay is part of the AdamSmithWorks series Just Sentiments curated by Daniel B. Klein and Erik Matson. New essays will be published on the fourth Wednesday of the month. You can read more about the series in this Speaking of Smith post, "Just Sentiments- Welcome!". Klein and Matson lead the Adam Smith Program in the Department of Economics at George Mason University, in association with the Mercatus Center. In the program, they study big ideas in jurisprudence, politics, ethics, and economics as they were pursued during the original arc of liberalism, especially in the 18th century in Britain.

Griswold, Charles L. 1999. Adam Smith and the Virtues of Enlightenment. New York: Cambridge University Press.
Hume, David. 2007. A Treatise of Human Nature. Edited by David F. Norton and Mary J. Norton. 2 vols. Oxford: Oxford University Press.
Livingston, Donald W. 1984. Hume’s Philosophy of Common Life. Chicago: University of Chicago Press.
Matson, Erik W. 2019. “Adam Smith’s Humean Attitude Towards Science; Illustrated by ‘The History of Astronomy.’” The Adam Smith Review 11: 265–80.
———. 2021. “A Dialectical Reading of Adam Smith on Wealth and Happiness.” Journal of Economic Behavior & Organization 184: 826–36.
Polanyi, Michael. 1962. Personal Knowledge: Towards a Post-Critical Philosophy. London: Routledge.
Smith, Adam. 1982a. Essays on Philosophical Subjects. Edited by W.P.D. Wightman and J.C. Bryce. Indianapolis: Liberty Fund.
———. 1982b. The Theory of Moral Sentiments. Edited by D.D. Raphael and A.L. Macfie. Indianapolis: Liberty Fund.