For a long time, I've watched people close to me struggle with questions of belief and doubt, of faith and skepticism. Like most believers, I've had my own difficulties figuring out how to deal with my personal mixture of uncertainty and conviction—both about general religious issues (Is there a God? Did Jesus really save me from my sins?) and about more specifically LDS themes (What is the spiritual status of the Book of Mormon? What does Joseph Smith mean to me?). Of course, I have no special expertise on these issues. However, my professional life as an academic researcher, in combination with my own personal experiences, may have given me a set of perspectives that I hope might be interesting and useful for some readers.

Most questions about faith eventually boil down to this: How could I know for sure that there is a God? In my experience, the only thoughtful people who can hope to avoid having to confront this question are those who are raised as atheists—and even some of these end up asking themselves whether there might be a God.

What I want to suggest in this essay is that our discussions of this question often get bogged down because we make some unreasonable assumptions about the nature of knowledge. I will briefly consider three interrelated issues here. First, is human knowledge objective or subjective? Second, is there only one kind of knowledge? Third, what is the relationship between knowledge and faith?

Probably most people intuitively think that knowledge, to be worthy of the name, must be objective and not subjective. Certainly, this is a common position (or the most common position?) among current and former members of the LDS church. A rhetorical touchstone for this position is the phrase: "as surely as I know the sun will rise tomorrow." Speakers use this kind of statement to imply a number of beliefs about the nature of the world. For instance, one assumption here is that such a thing as the sun actually exists and actually does rise every day. This statement probably seems so obviously true that it does not even deserve to be called an assumption. Yet, if we consider it carefully in light of modern scientific belief, this statement is in fact false. The sun is not currently believed to actually rise; rather, the Earth is said to rotate, giving humans who happen to be on the Earth the illusion of a sun that rises once a day (or somewhat less often in Chicago and Seattle). In other words, our natural knowledge that the sun rises every day is true, but only from our particular point of view. We almost always find ourselves caught in this kind of dilemma. The evidence that each of us has on which to construct our knowledge is, irreducibly, our own—so the resulting knowledge is always subjective in the specific sense that it originates from a specific subject, or person.

A very different philosophical position, often ridiculed under the names of relativism or postmodernism, holds that all human knowledge is inherently subjective and therefore—to a greater or lesser extent—unreal. This stance is less innately idiotic than many people often believe. Human knowledge about patterns of causation is notoriously unreliable, especially in contexts where randomized experiments are impractical. For example, informed individuals find the available evidence more or less compatible with literally dozens of different causal accounts of how people decide which candidate to support in elections.

Yet, I think it is a mistake to agree too quickly that all subjective knowledge is illusionary. Let us examine a bit more closely the idea of "subjective knowledge." First of all, it is evident that subjective knowledge cannot be the same thing as opinion. Opinion is merely a statement of an individual's preferences, whereas knowledge (other than, perhaps, self-knowledge) involves something more than the speaker's own preferences.

Second, it is obvious that subjective knowledge, like any other kind of knowledge, may be entirely false. Let me give you a rather vague personal example. For several years, I knew, based on personal experience, a great deal about a number of horrible things that had been done by someone very close to me. During recent months, I have learned that my prior knowledge was entirely false. I had been misled by a trusted friend of mine, who had helped me interpret my experiences in a way that created several false impressions. I now have what I consider to be rather more persuasive subjective knowledge about the innocence of the person that I had suspected for all of these years. To reiterate, knowledge, even when based on immediate personal experience, can always be wrong.

Thus far, our discussion is perfectly in keeping with the assertions of the postmodernists. Indeed, the only way that we can reject their claims is by an act of faith. People often fail to understand the intellectual seriousness of the postmodern challenge in this regard. Perhaps the greatest intellectual achievement of Western society, in my clearly inexpert view, is the demonstration that logic is entirely inadequate even to prove such a trivial matter as whether or not the keyboard on which I am typing this essay actually exists. I know that I experience this keyboard through my senses, but there is no logical reason to trust my senses. (Now less than ever—my senses have told me in recent years that Hobbits exist and that David Copperfield has magical powers.) Further, I know that my senses tell me that my wife also experiences the existence of this keyboard, but this is only meaningful if I trust my senses enough to believe their reports about my wife. Once again, there is no logical reason to do so.

Because of these problems, logic proves to be entirely inadequate as a basis for a theory of knowledge. Subjective knowledge cannot be fundamentally grounded in logic, for the simple reason that logic is never sufficient to convert experience into general principles. Instead, an act of fundamentally irrational faith is required if we are to believe the reports of our senses. Indeed, all of the knowledge produced by the natural sciences, not to mention the social sciences, relies entirely on the assumption that our senses are, to at least some extent, reliable. But, most people are willing to make this assumption. Further, rejecting this assumption is no more rational than making it, because logic certainly provides no evidence that our senses are fundamentally misleading us.

Now we come to the crucial question. Is faith, or religious conversion, irrational? Is religious knowledge meaningful at all? In particular, is it reasonable to for someone to interpret an emotional experience as a form of knowledge about the divine? Religious conversion is based on a decision to accept certain emotions as at least sometimes serving as a form of evidence about spiritual reality. Obviously, this decision is entirely irrational, in the specific sense that it has no logical basis. Indeed, the decision to accept some emotions as sometimes serving as a basis for spiritual knowledge requires a leap of faith that is exactly as irrational as the leap of faith that allows us to accept the evidence of our senses.

Subjective knowledge, of either the spiritual or the physical variety, is meaningful only if we accept the assumptions on which it is based. Yet this does not immediately make such knowledge meaningless. When we accept these assumptions, other aspects of our experience become comprehensible. It becomes reasonable to accept knowledge to the extent that it provides a useful organizing template for our subjective reality. Specifically, it is reasonable for an individual to accept an emotional experience as a message from the Holy Ghost about spiritual truth, if that interpretation helps a person make sense of aspects of the outside world, of other emotional experiences, of relationships with other people, and so forth. Whether the subjective knowledge behind a particular conversion experience, or any other knowledge claim, does so is beyond the scope of this essay. Nevertheless, I believe this is the appropriate standard to apply when evaluating claims of subjective knowledge in general, or more specific claims of spiritual knowledge about the divinity of Jesus, the nature of the atonement, or other issues commonly raised in discussions of LDS theology.