Beer may be made from many different ingredients, but beer is barley, for even when other grains are used, barley is included. We may say figuratively, then, that knowledge is our kind of beer, and scarcely can I drink enough of it but the drinking increases my thirst for more. But what the ingredients? Which the barley of our thinking? Four ingredients: reason, belief, ground, argument. Others seem species of these four. And each of these its own distinct place and function, beyond the bounds and constraints of which become destructive.

And it seems, at least from evidence here, that we won't agree on the most important ingredient. But I will argue for reason.

By reason I suppose I must mean logic, reason itself being the use of it, and the argument the incidental form it takes.

That leaves belief and ground. If argument is made with and of reason, it is built on some ground, the argument being as sound as its ground and no sounder - although with flawed reasoning easily weaker than its ground. Ground, then, as foundation. But made of what?

If knowledge, the hoped for result of argument, is the proposition that something is, then the ground seems to be not that some antecedent state is, but rather that it had better be! Ground, then, as imperative! The great difficulty with this being that it seems ultimately to be a matter of belief! Belief as being under all the turtles. But this "belief," though, in terms of ground, having absolutely nothing to do with any after-the-fact whole cloth claim or creation of desire.

Let me try to clarify these "beliefs" and any distinction between them. As ground, necessary, incontrovertible, axiomatic, granted. And these are themselves hard and substantial things. To be sure, such things are not always forever immutable; they can change. The relevant idea here that argument built on that foundation fails when the ground falls away. Also it seems to call them "beliefs" vitiates their strength as ground, obscuring that strength is if it were "mere belief." It seems altogether more accurate to simply call them grounds. And while believed, not properly beliefs so-called.

And mere belief that which is merely claimed. Unsupportable and unprovable, in some cases the unprovability being an essential feature. Religion an obvious source but also experience, practice, common sense, collected community wisdom: all these used not as ground but to underpin argument by claiming to stand as proofs of premises: all these, then, great impersonators of reason. For if they were objects of reason, then they would be provable, thus no longer mere beliefs.

Confusing grounds and (mere) beliefs seems at least one great threat to the enterprise of gaining knowledge, maybe the greatest, certainly one of the most pernicious. How to tell the difference? For this I have an unsatisfactory and partial answer. And it may be that a complete answer has a retroactive aspect, because at least it would seem that the judgment - itself an appeal to reason - would require the knowledge in question.

We can know mere belief by some of it signs. By the heat generated by the interaction of fanaticism, a part of all mere belief, and incoherence, the failure of reason intrinsic to every mere belief. These achieving a hot glow discernible in the argument, that when pressed can break out in a lava-like flow of words, "Told by an idiot, full of sound and fury, Signifying nothing."

Which seems harsh on mere belief. This belief can inform, direct, point, guide - we all have them - speculative belief having its values and virtues. But in particular and in every case lacking that substance required in argument, and in many cases, necessarily so.

I find presiding over all reason. The capacity to use tools to determine knowledge and winnow it from the chaff of unreason.