As promised, I’ve put a few tentative definitions below the fold, in hopes of clarifying questions in comment threads here and elsewhere. These definitions represent a starting point, not gospel. I’m not a philosopher, I haven’t spent much time reading epistemology, and I may mangle things badly. If so, polite critique will lead to productive revision, and hopefully progress toward broader agreement.
The essential terms under discussion here include “truth,” “truth claim,” “knowledge,” and “way of knowing.” “Science” and “religion” are also worth defining, but also rather less woolly, and less central to the issue.
What then, do I mean when I claim that there are multiple “ways of knowing”? Note here that this discussion takes off from a talk Eugenie Scott gave, a talk which I didn’t attend. So I don’t know how she defined that term, if at all. Nor do Russell Blackford or Jerry Coyne, in commenting on the talk, seem to offer any definition. And Google indicates that this is largely a term from pedagogy, as in John A. Moore’s Science as a Way of Knowing: The Foundations of Modern Biology. Thus, we’re basically starting from scratch. To start with, we’ll say that a way of knowing is a means of gaining knowledge.
This requires us to nail down “knowledge.” Russell Blackford proposes that “knowledge is, at the least, justified belief.” This leaves us to define both belief and justification. I think belief is sufficiently straightforward that I’ll leave it aside and tackle the issue of how one justifies belief. I note in passing that Blackford omits a common part of definitions of knowledge: truth. I think that’s a wise choice, as truth is slippery, and much scientific knowledge is probably wrong in at least some way, and it’s useful to treat the truth of a claim separately from how we came to have that knowledge.
According to the Stanford Encyclopedia of Philosophy:
Beliefs arise in people for a wide variety of causes. Among them, we must list psychological factors such as desires, emotional needs, prejudice, and biases of various kinds. Obviously, when beliefs originate in sources like these, they don’t qualify as knowledge even if true. For true beliefs to count as knowledge, it is necessary that they originate in sources we have good reason to consider reliable. These are perception, introspection, memory, reason, and testimony.
Restricting ourselves to scientific knowledge for the moment, then, we can recognize that knowledge can be acquired through experimentation (a combination of perception, memory, and reason), and through testimony of other scientists, who either themselves went through that process of experimentation or who have what they believe to be reliable testimony from the scientists who did. Introspection, the SEP adds, has a special status:
Through introspection, one knows what mental states one is in: whether one is thirsty, tired, excited, or depressed. Compared with perception, introspection appears to have a special status. It is easy to see how a perceptual seeming can go wrong: what looks like a cup of coffee on the table might be just be a clever hologram that’s visually indistinguishable from an actual cup of coffee. But could it be possible that it introspectively seems to me that I have a headache when in fact I do not? It is not easy to see how it could be. Thus we come to think that introspection has a special status.
Some might disagree that it deserves this status, but it is at least plausible, and in practice, it seems wrong to tell others that they are wrong about how they feel, even though they might be, as they might be wrong about why they feel the way they do.
So it strikes me as fair to say that knowledge is belief justified by (rooted in) reliable testimony, reliable memory (remembered dreams, “recovered memory,” vague recollections, etc. thus being excluded), reliable introspection (has your gut feeling often led you astray? has a given stimulus caused similar feelings before?), reliable reasoning process, or reliable perception. I recognize that reliability is itself a disputed point in this field, but I like it as a starting point. It does raise a small issue of how you gain knowledge of reliability; my inclinations lean towards a philosophical Bayesianism but not strongly. Let’s not get too far into the weeds.
To me, knowledge is basically a truth claim, one that is testable by further experience, by comparison with other sources of justification, etc. As a professor of mine once said, truth is the intersection of multiple independent lies. He said that in the context of multivariate statistics, but I think works equally well in the wider world. Dr. House would certainly agree. However reliable memories, perceptions, witness, logical chains, or introspection might be, they are sure to be wrong, or wrongly interpreted. More lines of evidence will tend to eliminate wrong answers, but cannot guarantee that you arrive at the right answer. Thus, a truth claim can be refined, but our fallible human minds are unlikely ever to get it entirely right. A truth claim is a statement about the world (either the external world, one’s internal state of being, or imagined worlds), which can be evaluated through future experiences.
Truth, then is a gradient. Truth is a full, complete, and accurate account of some aspect of reality, including one’s internal state and abstract philosophical entities. Certain beliefs, when justified by more lines of evidence (including non-empirical evidence like testimony, memory, introspection, and chains of reasoning rooted in such evidence) are likely to be truer than those backed by less evidence. Scientific truth claims are notable for being, at least in principle, falsifiable by observations from our intersubjective experience of the world, though evidence for them can come from other sources. Consider Kekulť and his daydream about snakes which led to the discovery of benzene’s structure. That initial insight from introspection led to further experimentation, which led to growing confidence in the truth of benzene’s ring structure. However unlikely evidence falsifying that belief could still be found, so I would tend to regard this not as a truth, but as a truth claim, albeit one which is almost certainly true.
To return, then, to ways of knowing, I’ll define them as systematic methods of evaluating truth claims against new sources of knowledge, whether those sources be experiential, introspective, logical, or rooted in testimony from others. These sources inevitably include self-described revelation, description of revelation by others, and appeals to authority. By systematic, I mean that one can identify consistent ways of assembling and evaluating lines of evidence, repeatable at least in principle by others, even if a given evaluation cannot (if it relies on introspection, for instance).
That, hopefully, is a start. A rough start, one which requires substantial fleshing out I’m sure, but should give readers and commenters some basis for continued discussion.