Smith explains Bacon’s defense of certainty and his contributions to a secular worldview.

George H. Smith was formerly Senior Research Fellow for the Institute for Humane Studies, a lecturer on American History for Cato Summer Seminars, and Executive Editor of Knowledge Products. Smith’s fourth and most recent book, The System of Liberty, was published by Cambridge University Press in 2013.

In my last essay I discussed the influence of Pyrrhonic skepticism on modern thought, and how skeptical arguments were used to support the fideistic contention that reason is unable to generate certainty, leaving us no choice in religious matters except to rely entirely on faith. Among the important consequences of Pyrrhonism were the replies it evoked from philosophers who attempted to refute it. Two of the most important attempts were undertaken by Rene Descartes (1596–1650) and Francis Bacon (1561–1626). Here I will discuss the arguments of Bacon, who was a seminal figure in the development of modern secularism.

It is difficult to imagine the course that modern philosophy might have taken if Rene Descartes and Francis Bacon had never existed. Both are widely recognized as key figures in the history of modern philosophy, although for different reasons. Descartes is often credited as the founding father of the philosophical trend known as Rationalism, whereas Bacon, if he has not received similar credit as the father of modern Empiricism (an honor usually reserved for John Locke), has at least attained the status of its godfather. And Bacon’s extraordinary importance as a philosopher of science has long been appreciated.

Although Bacon was accused of being a secret atheist, his belief in Christianity, though extremely liberal by the standards of his day, appears to have been sincere. He flatly rejected a literal interpretation of the Bible in favor of doctrinal pluralism, maintaining that biblical passages should serve as “infinite springs and streams of doctrines.” Because biblical writers typically expressed themselves through metaphor, Scripture should not be used as a source of scientific knowledge, nor should it serve as a basis to criticize the conclusions of science. The spheres of religion and science should be kept completely separate, neither being allowed to impinge on the domain of the other. The various “mysteries” of Christian revelation, such as the Trinity, are incomprehensible to reason and therefore must be accepted entirely on faith. When theology is permitted to transgress beyond its proper sphere, “every development of philosophy, every new frontier and direction, is regarded by religion with unworthy suspicion and violent contempt.” Thus, as Peter Urbach (Francis Bacon’s Philosophy of Science: An Account and a Reappraisal, 1987) observed, Bacon “banished the Bible as a source of information for the scientist.”

In driving a wedge between philosophy and theology by insisting that we “give to faith only that which is faith’s,” Bacon gave his blessing to a secular tendency that, like a slow‐​acting poison, would eventually undercut the foundations of orthodox Christianity. As Franklin Baumer, commenting on the rise of seventeenth‐​century secularism, explained in Modern European Thought: Continuity and Change in Ideas, 1600–1950:

Secularism, unlike free thought, posed no threat to particular theological tenets. What it did was to outflank theology by staking out autonomous spheres of thought. The tendency was, more and more, to limit theology to the comparatively restricted sphere of faith and morals.

Bacon’s scientific secularism, while it did not challenge Christianity per se, exiled God to the nether regions of faith and theology, thereby denying to him any direct role in the acquisition of natural knowledge. “God,” according to Bacon, “worketh nothing in nature but by second causes.” To speak of God as the first cause is a matter of theology, not science, and reasonable men “do not unwisely mingle or confound these learnings together.” So consistent was Bacon’s secularism that he rudely dismissed any reference to miracles in accounts of natural science and history: “[A]s for the narrations touching the prodigies and miracles of religions, they are either not true, or not natural; and therefore impertinent for the story of nature.”

It is fair to say that Bacon had more influence on the rise of secularism than did Descartes, who assigned to God a key role in his philosophical system. Far more significant, however, is the fact that Bacon and Descartes differed substantially in their views of human reason (or “understanding,” as Bacon, Locke, and others in their tradition often called it). In a nutshell, we may say that for Descartes reason is an infallible faculty of cognition, an instrument that cannot fail in its quest for absolute certainty if used properly. For Bacon, in contrast, reason is inherently fallible; it is prone to error even in the best of circumstances, so we must stand perpetually on guard, willing to correct or revise our present beliefs.

Although both Bacon and Descartes rejected the epistemological skepticism of Montaigne and other fideists—according to whom we must rely on faith to attain a certainty that reason is unable to provide—their approaches to this problem differed significantly. Bacon, unlike Descartes, did not attempt to overthrow skepticism with a definitive theoretical refutation; he did not employ the Cartesian method of systematic doubt in an effort to establish an infallible criterion of knowledge, such as the intuitive grasp of clear and distinct ideas. Rather than employ this kind of shortcut, Bacon plotted a course to certainty that must be traveled step‐​by‐​step, and he insisted that we must sometimes traverse the same ground over and over again in order to check our bearings. Certainty, in other words, does not reveal itself to reason in a flash of insight, but instead is an elusive ideal that reason may attain to a greater or lesser extent, depending on the circumstances.

As Bacon saw the matter, the skeptical argument that we can never achieve certainty amounts to little more than a pretentious bit of futile and self‐​defeating dogmatism. The skeptic, having proclaimed that infallible certainty is unattainable, never tries to attain it because he knows that man is a fallible being for whom error looms as an ever‐​present possibility. To this objection Bacon responded, in effect, that to define “certainty” in terms of infallibility is to make certainty unattainable to human beings at the outset and thereby render the concept of certainty altogether irrelevant to human knowledge. Rather than blocking the path to knowledge with an arbitrary and unrealistic definition of “certainty,” we should recognize that the quest for knowledge is beset with difficulties; and then, through a process of trial and error, we should see whether these difficulties can be overcome. Bacon wrote:

Our method and that of the skeptics agree in some respects at first setting out, but differ most widely, and are completely opposed to each other in their conclusions; for they roundly assert that nothing can be known; we, that but a small part of nature can be known, by the present method; their next step, however, is to destroy the authority of the senses and understanding, whilst we invent and supply them with assistance.

As part of his attack on skepticism, Bacon distinguished particular doubt from total doubt. Particular doubt, or doubt that arises in regard to a specific knowledge claim, is useful both as a spur to inquiry and as an antidote to the proliferation of error, as when a false conclusion is inferred from a premise which has not been sufficiently justified. Total doubt, in contrast, is the universal doubt of skepticism, and this is what Bacon regarded as a rather cowardly surrender to the difficulties that frequently arise in our quest for knowledge.

Skeptics sometimes pointed to the diversity of philosophic opinions to support their contention that certainty is unattainable, but Bacon was unconvinced. Nature is far more complex than the mind of man, so the same essential truth may be expressed in different ways by different thinkers. Scientific knowledge, cumulative and open‐​ended, progresses as one scientist improves upon the contributions of his predecessors. The human intellect is not an infallible instrument – far from it – but to say that an instrument can sometimes fail is not to say that it must necessarily fail in every case. Just as the human hand could not construct architectural wonders without the aid of external tools, so the human intellect cannot attain certainty without the aid of objective methods to test and validate our knowledge claims. Again quoting Bacon:

The unassisted hand and the understanding left to itself possess but little power. Effects are produced by the means of instruments and helps, which the understanding requires no less than the hand; and as instruments either promote or regulate the motion of the hand, so those that are applied to the mind prompt or protect the understanding.

The skeptic who denies that we can ever attain certainty is like a person who, after observing the limited power of the naked hand, declares that man will never be able to build a cathedral. The skeptic, trapped in a sophistical web of his own making, perpetually whines about the obstacles to knowledge. Bacon, on the other hand, argued that the time of the philosopher would be better spent in devising methods – cognitive instruments, in effect—that would enable us to overcome those selfsame obstacles.

Thus if Bacon’s stress on the inherent fallibility of reason did not land him in skepticism, this is because he rejected infallibility as a criterion of certainty. Certainty is something we achieve through sustained mental effort, a laborious and systematic process of trial and error, not something that is revealed to us in a flash of infallible insight. Certainty is achieved piecemeal through the investigation of particular knowledge claims, not wholesale through a process of deductive reasoning based on clear and distinct ideas. Our ideas, if they are to generate useful knowledge, must be framed according to our experience of nature; and this experience, if it is to be reliable, must be subjected to objective methods of verification.

The foregoing must be kept in mind if we are to appreciate Bacon’s celebrated discussion of the various Idols, or “fallacies of the mind of man,” that hinder our quest for knowledge. Bacon was the first great pathologist of human reason, and his mode of analysis—a mixture of psychology, sociology, and epistemology—was used by later philosophers to explain why reasonable people with good intentions can, and often do, hold incompatible beliefs. It was largely owing to Bacon that religious dissent, which had previously been condemned as the deliberate (and therefore sinful) rejection of divine truth, came to be regarded instead as the innocent byproduct of human fallibility. And this doctrine of the natural diversity of opinion (especially as developed by John Locke) was destined to play a key role in the struggle for religious toleration.

Bacon’s basic point is quite simple and, from the perspective of a Cartesian rationalist, quite disturbing: There is no natural harmony or correspondence between the world of ideas and the world of nature. If, as the rationalist maintains, our sense organs are inherently untrustworthy and liable to lead us astray, the same is true of reason itself. The human intellect has its own distinctive characteristics, a nature apart from that which it seeks to know. Understanding is not a passive process in which the intellect merely reflects the external world of nature. Rather, the intellect actively contributes to the cognitive process, leaving indelible marks on its final product. Thus, “the human mind resembles those uneven mirrors which impart their own properties to different objects, from which rays are emitted and distort and disfigure them.” These natural distortions are what Bacon calls Idols, or false notions, of the human understanding.

Bacon divided his Idols into four principal categories: (1) Idols of the Tribe “are inherent in human nature and the very tribe or race of man.” (2) Idols of the Cave pertain to the individual, for “everybody (in addition to the errors common to the race of man) has his own individual den or cavern, which intercepts and corrupts the light of nature….” (3) Idols of the Market are “formed from the commerce and association of men with each other….” (4) Idols of the Theater “have crept into men’s minds from the various dogmas of peculiar systems of philosophy…as so many plays brought out and performed, creating fictitious and theatrical worlds.”

The human understanding, according to Bacon, does not operate in isolation apart from the will and affections. Our desires and feelings influence how we think. We are more likely to believe something that we wish were true, the comfortable and the familiar, rather than something difficult, disturbing, or unconventional. We also tend to develop a vested interest in our beliefs, defending a pet theory because we created it, worked hard on it, or simply because of its familiarity.

Bacon maintained that people who think differently will often exhibit different biases. People with strong powers of observation, for example, may attribute too much importance to minor differences among things, whereas other people may overemphasize their similarities. In any case, to examine our own beliefs objectively is extremely difficult, given the many subjective factors that affect our understanding. But Bacon did offer a valuable piece of advice, namely, that we should be particularly suspicious of those theories which give us the most satisfaction, subjecting them to rigorous scrutiny and criticism.

Perhaps the most radical aspect of Bacon’s approach was his unequivocal rejection of final causation as a legitimate mode of explanation in the physical sciences. To appeal to a final cause is to explain a phenomenon in terms of its supposed purpose; and though Bacon’s critique of this method was primarily directed at the Aristotelians of his day—known as “scholastics” (i.e., “schoolmen”) because of their dominant presence in European universities—it had far broader implications for the Christian worldview. To banish final causation from the realm of explanation is to banish all references to a divine purpose in the universe. God, in the hands of Bacon, became an absentee architect of creation—a first cause who, having created the universe, thereafter left it alone to operate according to the secondary causes of natural law. It is therefore understandable why Bacon was universally praised by later deists.

Indeed, depending on how we read Bacon, he may even have rejected the notion of a first cause altogether. According to Bacon, we cannot reasonably demand an explanation for existence, because something must first exist before it can function as a cause of something else. So why do so many people seek to go beyond the brute fact of existence and posit God as a first cause? Because, said Bacon, the human mind is active and restless; it is engaged in a perpetual quest for intelligibility, for ultimate explanations that will satisfy its desire to understand. But when reason is unable to satisfy this metaphysical urge, as is often the case, the imagination steps in with fanciful explanations of its own.

This is what happens when the mind moves up the ladder of cause and effect and posits God as the ultimate cause of everything else. This is a fancy of the imagination, not a judgment of the understanding. Reason tells us that “the greatest generalities in nature,” such as the fact of existence, must be accepted “just as they are found,” and that such facts are “not causable.” Existence, in other words, is a causal primary, the ultimate foundation on which all explanations depend, an irreducible fact beyond which the mind cannot go. But this is not what the mind wants to hear; it cannot find satisfaction in being told that its metaphysical journey must end, abruptly and unceremoniously, at the impenetrable wall of existence. Thus does the imagination satisfy this metaphysical desire at the expense of reason, and thus does another Idol take its toll.