To Alan:
You and I are certainly moving closer on some things but perhaps apart on others. First a couple of comments:
"The particular conclusions of Epicurean physics that I disagree with are 1) swerve, 2) infinity of the universe, and 3) eternality and immutability of atoms." <<< Well you're sure listing some big ones but at least we are being clear. ![]()
"This is how I understand how (through DeWitt) Epicurus derives the above. Regarding the swerve: Premise 1) The atoms move in straight lines with constant speed. Premise 2) If the atoms never contact one another, there could be no macroscopic objects. Premise 3) We observe that there are macroscopic objects. Conclusion ) Therefore, the atoms must swerve." <<<< I think you are correct in large part as to Dewitt, but I think even DeWitt factored in he deduction based on what we observe about free will. I think you will be interested in an article some of us recently discussed by David Sedley (I will get the title and paste here) where Sedley contends that Epicurus came to the conclusion about the swerve from another direction primarily, rather than physics. Regardless of which approach is correct, it appears the swerve was a deduction and was apparently not considered to be a topic of prime importance by Epicurus.
"Lastly regarding the eternality and immutability of atoms, I am not sure if he deduced these or if he held those to be axiomatic." << I would project that this too was based on deductive logic, as DeWitt contends. Of course in the Epicurean scheme, deductive logic is tied as tightly as possible to observations, so they go hand in hand.
"We can still employ the Canon and the Ethics in our lives because at the root of both is an appeal to the metaphysical position of naturalism/materialism and empiricism, and a hard rejection of supernaturalist explanations of things. There are still no supernatural gods, no ideal forms (in reality, but perhaps in our imagination), no compulsory virtues, no fatalism (we do not need the swerve to defend free-will), and no afterlife. We haven’t lost any of the important Epicurean conclusions by dismissing the results from the old physics." <<< I think in response to this Epicurus would say in part something like, "Ok Mr, Reyes, if you don't like mine, what is YOUR explanation for these physical phenomena?" And if you are able to give a coherent one which is understandable to ordinary people, without leaving them dazed in conclusion, then possibly you would be right when you say that 'we haven't lost any of the important Epicurean conclusions.' Otherwise you are making assertions on which there is no good reason to have confidence than if you asserted the opposite about your positions."
Because I think that Epicurus would also say, further, that in the absence of a coherent and understandable explanation of the universe which allows us to have confidence in our conclusions, then theories which end up saying simply "we don't know" about the important questions about our / humanity's place in the universe end up as a practical matter undermining our ability to live happily. There are a number of statements to that effect in Epicurus, one of which is in the letter to Menoeceus that it would be better to believe in a false religion than to believe that we where the slaves of hard determinism and thus had no power whatsoever to effect our future happiness.
As for me personally, I enjoy reading scientific material, and I welcome every bit of new evidence I can find. But I also conclude more strongly as I get older that it is rare for "science" to come at us totally without an "agenda" of the carrier, and in many if not most cases, there is an "agenda" behind what is presented so as to emphasize uncertainty and doubt while replacing it with attitudes of radical skepticism and other damaging viewpoints. There are exceptions to this, and I understand from my limited reading that Victor Stenger is one.
I should also say that I am cautious not to attempt to go toe to toe on the details of the latest research, but I do harbor the strong suspicion that the attitude of many theorists is flawed because they do not understand, or they reject, the ultimate philosophic approach that we are discussing. How many times do we see people talk about an "expanding universe" without making very clear that we are talking about "the universe we have observed so far?" When someone fails to acknowledge that limitation in their position I almost automatically disqualify their sweeping conclusions. Same with Lawrence Krauss and his "A Universe from Nothing" book titles which gloss over that his definition of "nothing" is not consistent with the literal philosophic definition of the word.
So in conclusion at this point I can fully agree with you that some particular scientific positions certainly need to be revised, but I also think Epicurus would say that tearing down our confidence in a natural understanding of our place in the universe, without replacing it with something more firm based on better science, is extremely dangerous, And the worst possible variation of that would be to contend that we should "have faith in science" which is really another bottom line of what I detect in the position of some advocates. There is ultimately no such thing as "science" - the valid part comes down to real people talking about their observations from experience. In the practical experience of most (if not all) humans, productive discussion of science requires a framework of thought that makes sense and is consistent with the information available to us through our senses.
If you rip away the framework that gives us confidence in our conclusions, you end up as doing nothing more than making assertions without any grounds for confidence in them, thereby undermining our confidence in living our own lives. In the words of book four of Lucretius, "And though reason is not able to assign a cause why an object that is really four-square when near, should appear round when seen at a distance; yet, if we cannot explain this difficulty, it is better to give any solution, even a false one, than to deliver up all Certainty out of our power, to break in upon our first principle of belief, and tear up all foundations upon which our life and security depend. For not only all reason must be overthrown, but life itself must be immediately extinguished, unless you give credit to your senses. These direct you to fly from a precipice and other evils of this sort which are to be avoided, and to pursue what tends to your security. All therefore is nothing more than an empty parade of words that can be offered against the certainty of sense." (Daniel Brown version)