As several of Locke’s interpreters have noted, however, his distinction does not hold.27 Locke immediately undermines his own clear contrast, ultimately shifting to a quantitative distinction between forms of belief and opinion that he treats as knowledge. He cites other forms of knowledge, including habitual knowledge based on the memory of perception; sensitive knowledge of the existence of external objects; and demonstrative knowledge, which is mediated by other propositions. Locke assigns the term knowledge to all these, but none of them uphold the same immediate and passive reception initially required for knowledge. Consequently, as Casson summarizes these moves, “Locke pushes the greater part of our knowledge in the direction of voluntary belief” and probability effectively takes over the realm of knowledge.28
Locke never fully abandons his claims to certain knowledge, notably asserting that “Morality is capable of Demonstration, as well as Mathematicks” (3.11.16; see also 4.3.18). Indeed, there are for Locke cases in which such assent will be forced by demonstrably true claims, but they turn out to be infrequent and highly limited in practical use. These truths, such as “Where there is no Property, there is no Injustice” remain meaningful only at the level of abstract definition. Locke holds out the promise of demonstrative certainty in moral philosophy but never develops it, and it is unclear whether it could ever be developed.29 In other words, Locke reserves a category of knowledge that is certain and immediate. Over the course of book 4 of the Essay, however, that category comes to occupy an increasingly circumscribed and irrelevant place in the work’ s central concern with the conduct of human understanding and action. Belief or opinion based on active judgment of when to give assent takes over most matters before the understanding. The narrow scope of demonstrative knowledge and the vast, expansive terrain of judgment are brought together under the chapter heading “Reason.” In this comprehensive form, reason emerges, in William Walker’s words as “the faculty that bridges the supposedly distinct faculties of Knowledge and Judgment and that assesses and is affected by all ideas, whether they make up knowledge or probability.”30 Locke resituates reason such that it no longer sits on the side of either philosophy or opinion. Rather, reason is expanded to encompass judgment in situations both certain and uncertain, but mostly uncertain. Despite the lack of certainty, Locke speaks of judgment as sufficient for the purposes that humans face as moral and instrumental agents in this life and the next. Judgment in practical matters is both necessary and sufficient for even the weightiest matters of human action and responsibility. As Kirstie McClure explains, for Locke, “the dilemma confronting every human agent was one not of metaphysical speculation but of existential risk and practical judgment.”31
Recognizing Locke as a theorist of judgment may seem discordant with his appeals throughout his writings to foundationalist terms and tropes, for example, the grounds of knowledge, philosophical and political origins, and nature as representing both a human condition (the state of nature) and functioning as an object of scientific inquiry. It certainly challenges the construction of his work as fundamentally divided. However, it also challenges those who see a more unified body of work in which practical judgments find their validity by recourse to epistemological or moral foundations, whether empirical, rational, religious or some combination of these.32 Instead, Locke’s appeal to such foundationalist terms sets up a problematic of judgment that does not guarantee verifiable conclusions, at least not in this life. It is this problematic of judgment that, as we will see in the forthcoming chapters, bridges his philosophical, moral, and political concerns.
As we now see, Locke’s claim to experience and his overriding concern with judgment emerge from a period of cross-pollination between traditions of rhetoric and of philosophy. While new natural philosophers adopted the older rhetorical language of experience, opinion, and probability, they also reinvented that language for their novel scientific projects. Such reinvention, however, does not necessarily mark the severing of rhetoric’s influence on the notion of experience.33 Rather, the reworking of an old language for new purposes and the desire to disseminate sensible experience and practices of observation to an emerging public made vivid language, analogies from nature, and the capacity to persuade an audience of probable truths all the more important. In other words, the reinvention of a language of experience and a mode of judgment out of fraying philosophical and humanistic traditions relied on rhetoric in new, distinctive ways.
The Culture of Epicurean Materialism
I have so far placed greater emphasis on how the notion of probable judgment drawn from experience borrowed from the rhetorical tradition and was reinvented for the scientific purposes of emerging claims to experience in natural philosophy. This preoccupation with probabilistic judgment was by no means limited to what we would recognize today as an emerging scientific realm. On the contrary, it came to span many types of inquiry that included not only philosophy and science but also history, religion, language, and politics.34 It became, in Richard Kroll’s words, “an entire symbolic cultural mode.”35 This cultural mode was one of Epicurean materialism, inaugurated by Gassendi’s revival of Epicurus, via the poetry of Lucretius (translated into English for the first time in 1656), and the reconciliation of the ancient philosophy with Christianity.36 It cohered around the epistemological commitments we have been examining—probable knowledge based in experience, an ineliminable condition of contingency, a mitigated form of skepticism—as well as a revival of Epicurus’s commitments to atomism and hedonism. Emerging in the aftermath of the English civil wars, these widespread commitments and themes contributed to an anti-Cartesian perspective held by Gassendi, as well as Boyle, an important intellectual influence for Locke, and Hobbes, in differing ways.37 Notably, in contrast to Descartes and Spinoza, Gassendi insisted on the necessity of rhetoric for this new method and epistemology.38
Language was a matter of significant interest and concern from the beginning for the New Scientists. Just as Aristotelian and humanist approaches to empirical inquiry fell short, so too did they fail to offer an appropriate language with which conduct the methods and convey the findings of the New Science. Bacon first suggested aphorism and analogy as particularly useful styles, but his model was not adopted by later generations of the Royal Society. By the second half of the seventeenth century, the distrust of Aristotelian and humanist practices were combined with a particularly intense hostility to the unstructured, emotive, and mystical rhetoric of nonconformist sects (enthusiasts) who also rejected their predecessors. A new style for the New Science sought to reject the highly ornate, disputational, and impassioned speech of these various opponents, for purposes of knowledge as well as politics. Nevertheless, rhetoric remained essential for their philosophical and practical purposes.39
Language and a renewed interest in the workings of the material world were not necessarily opposed but were brought into close relation in this new materialism, as exemplified in an oft-cited analogy by Lucretius comparing letters with atoms.40 Where materialism today often connotes mechanism, contingency was instead a central commitment for this seventeenth-century materialist culture along with a rhetoric that promoted that sense of contingency. Objects of inquiry, natural, historical, or textual, were approached as fragments or atoms from which to draw hypothetical inferences. Such atoms—whether scriptural fragments or natural evidence—were resistant, but not immune, to interpretation. Their stubbornly fragmented nature served to highlight the artificial and contingent work of drawing meaning from the particulars of experience.41
The atomistic nature of the material world pressed the need for the intervention and artifice of the interpreter or judge. Self-conscious activities of interpretation and judgment were seen as essential to moral, historical, scientific, and philosophical knowledge, whether in reading scripture, ancient texts, or the Book of Nature.42 Accordingly, Epicurean writers engaged in a self-narration of their own reading to “allude to and dramatize the reader’s necessarily contingent activity when faced with the text,” revealing to readers the conditions of the texts own production, particularly its figural devices.43 Performing its own creation, especially its rhetorical creation, proceeded, at least in part, through certain conventions