[Part of The Molyneux Project; read the main critique here]
A warning: I can't imagine that anyone will find this post interesting. It's probably for the best that it's completely ignored by anyone who isn't a total philosophy nerd. I promise, this is not the kind of thing I want to be writing about, and I'll be keeping posts like this one to a minimum.
Since last night, I've had some time to go over my questions to see if I could figure out how they might be answered. The first question related to what Stefan was trying to demonstrate with his three examples of the "relative" nature of truth. I think the answer might simply be that Stefan was trying to say that our evaluations of certain things depend on more than the nature of the things themselves. That is, a healthy man doesn't change when others become more healthy; Newtonian physics becomes no less flawed when we use it to approximate the behavior of matter in simple calculations; gains in water purity are not inherently valuable at low increments, nor inherently undesirable at high increments. What changes is within us. In other words, value is subjective.
If I have interpreted Stefan correctly, then what threw me off, I think, was Stefan's use of the words "truth" and "relative." That value is subjective is uncontroversial; economists have long acknowledged that to be true. An object may inherently be potentially useful for achieving certain ends, but it's an act of the mind which ascribes value to such an object for this capacity. The classic example is crude oil, which was long considered an undesirable polluting substance until its usefulness was discovered. Oil gained no new physical quality upon the discovery of its usefulness, but it unquestionably became more valuable.
I want to make sure it's clear, though, that I've just put words in Stefan's mouth. It's fully possible that he intended to demonstrate some other point through these examples, which I am obscuring with this discussion. If that's the case, then I'd appreciate it if my error were pointed out, and the correct idea explained. Otherwise, I think it's safe to move on.
My second question pertained to Stefan's account of logic. Reading over what I wrote, I'm thinking I didn't do such a good job explaining my confusion. What I had in mind, and didn't realize that I should have to say, is that I am presupposing the rules of logic to be necessarily true. They are a priori truths. I am also presupposing that there is a substantive difference between a logical falsehood and a contingent falsehood. That is, I think that the falsehood of "1+1=3" is a different sort of thing than the falsehood of "My computer is an Apple" (it's actually a PC).
But if one accepts logical fatalism (the view that all propositional statements are either true or false, and that if something is true, then it is necessarily true, and if something is false, then it is necessarily false), then both statements would be necessarily false. Given that Stefan has stated that he is an athiest and believes that all matter must behave according to immutable laws, it seems fair to suppose that he is a logical fatalist (denying logical fatalism would require that he either claim that this universe could have not existed, or that the state of a material system is not determined by its previous state and the laws of nature). Accordingly, Stefan could be suggesting that in this universe, it's not possible for the person who was being addressed in the example to do the three things Stefan mentioned. Accordingly, it would be necessarily impossible for him to do any of them.
Stefan would still need a further step in order to answer my objection. He would have to say that in a logical fatalistic framework, true propositional statements are rules of logic. I don't think I've ever heard anyone argue that before. But if he did say that, then he could coherently argue that all three of his examples represented instances of logical impossibility. It seems to me that we should resist this conclusion, though, because it completely abandons the meaning of the word "logic," as it's traditionally used, and rests on such controversial underpinnings that it practically begs the question.
Again, I should be clear that Stefan hasn't said any of the things that I've proposed that he could say in defense of his examples. I think it's far more likely that Stefan just made a mistake here. I was only trying to be charitable.
I don't have much of a problem with my third point, except that I think I made it sound like the three possible meanings I discussed were the only things Stefan could have meant. I didn't intend to suggest that; I was only trying to think up a few possibilities. If Stefan meant something completely different, then I'd love to know.
I still can't figure out an answer to my fourth question, so I think I'm happy with what I've written so far. I still think my two objections in the first part of the critique are right, though I'm definitely going to have to refine them if I ever want to officially pose them to Stefan.
So that's good for now. I'd like to move on to the next bit of the book, but my project has hit a bit of a snag. For whatever reason, I haven't been able to access the file Stefan sent me with the PDF of the book. I e-mailed Stefan about it, and hopefully I'll be back in business soon.