But I want to look at a slightly different (although related) issue here. Howard-Snyder says:
We wonder why water moves downhill, speaking literally. We are told that it seeks the lowest point it can ﬁnd. That might be a start at gaining understanding, but we should not be satisﬁed. Why? Because water does not ‘seek’ the lowest point it can ‘ﬁnd’, speaking literally. Those are metaphors. We want more. Fully successful metaphysical enquiry–in theology as elsewhere –ultimately demands the stone-cold sober truth, spoken literally.
This claim that Fully successful metaphysical enquiry ultimately demands to be expressed literally is one that I suspect has a lot of plausibility to people. However, I think one should ask what this 'demand' is. And I think when one does, one finds that the claim is probably not true. I mean, Howard-Snyder can't even formulate it without doing so metaphorically; 'stone-cold sober' is a metaphor when applied to truth, as is 'ultimately demands'. His own principle would require us not to be satisfied with this characterization.
The real reason why 'water seeks the lowest point it can find' is not completely satisfying is that it only improves on 'water moves downhill' by clarifying that water's moving downhill is not a matter of chance but due to something about water itself. It does not tell us anything else about this something-about-water-itself; 'the lowest point' is arguably nothing more than a minor clarification about what we take the direction 'downhill' to mean, i.e., toward the lowest point. There is obviously a lot of room for more specification here, and that is what leaves us unsatisfied -- we haven't moved very far in the inquiry. Our next question would be something like 'what is involved in this seeking', but this is not due to its being metaphorical. Suppose the claim had instead been, 'Water is such that it flows coherently in the direction of the lowest point'; we would still want to know exactly the same thing, namely, what is involved in this flowing-coherently-in-a-direction? What's unsatisfying is that there is still obviously so much to know. It has nothing to do with the language in which we are expressing it. A physicist can perfectly well use 'black hole' to describe black holes, even in a fully rigorous and precise discussion of black holes, despite the fact that 'black hole' is a metaphor. His discussion will not be less satisfying merely because he didn't use a more literal expression. One notices, in fact, that physics gets more metaphorical the more rigorous it gets, as long as they are not simply speaking in equations. This is because the metaphors actually have a use in helping to describe things rigorously when our vocabulary is limited. If you look at other fields -- ethics, even mathematics, one finds a similar process. There is no reason to think this will not be generally true.
In any case, there is a straightforward reason to reject the claim that fully successful metaphysical enquiry ultimately must be expressed literally. The distinction between literal and figurative is entirely an artifact of how we set up our vocabulary. We see this with dead metaphors. 'Black hole' is metaphorical to us; but a hundred years from now, people might use 'blackhole' to describe the same thing and not see the metaphorical components; to them it could well be just the word for a black hole, and not convey any notion of 'hole that is black'. One also sees in history cases of fluctuation -- 'light' is perhaps one of the most important examples, since the word (and its cognates in other languages) has wavered all over the place. Is it a metaphor to call reason 'light'? Well, if you mean by 'light' primarily sensible, physical light, then obviously it would have to be; but the word 'light' has not always been taken so narrowly, and if you take it to mean 'source of action that makes something evident', which it has often meant, then calling reason 'light' is not a metaphor. And as it turns out, nothing fundamental hangs on the difference; 'light' (and its cognates) has applied to essentially the same things for centuries regardless of whether we were taking it literally or metaphorically. You can say the same things about the same things, as long as you are consistent. Indeed, unless you are actually talking about the meaning of the word itself, there needn't be any difference in the words you use. This all follows because the literal/figurative distinction is a distinction in how we are using words; and nothing is really harmed as long as we aren't switching back and forth.