Is Trinitarian theology essentially linked to the "pro-slavery tradition"?

My good Jehovah's Witness friend, Edgar Foster, who continues to run his arguments against Trinitarian theology by me from time-to-time, recently sent me an email containing the tacit suggestion of an argument derived from a book by Kevin Giles, The Trinity and Subordinationism (InterVarsity, 2002). Apparently, Giles suggests that the "proslavery tradition" of theological interpretation is a historical consequence of the subordinationism implicit in the doctrine of the Holy Trinity. Giles points out that both the Old and New Testaments accept slavery, along with the subordination of women as facts of life without direct criticism. St. Paul's discussion in the Epistle of Philemon is well known on the issue. Further, Giles notes that similar attitudes of seeming indifference to slavery can be found in the history of Christianity. Of particular interest seems to be the statements of certain evangelical Protestants during and after the period of widespread acceptance of slavery in the history of our own Republic. The following is what I said by way of reply to Foster:

First, I think you'll agree with me that a case against slavery would be very difficult to make from the Bible. This may be troubling to
those of us living in the contemporary West (I think it is), but that hardly changes things. Most of the visceral reaction we feel against slavery today comes, I think, not from our reading of the Bible, but from our own culturally-informed reading of history. I think you would agree, would you not?

In that sense, I think the issue of slavery is much like three other classic issues in terms of their relationship to the Bible: (1) monogamous marriage, (2) the sanctity of life from conception to natural death, (3) the doctrine of the Holy Trinity. (See, for example, Mark P. Shea's argument in By What Authority? An Evangelical Discovers Catholic Tradition.) My hunch is that it would be very difficult to make a conclusive case for any of these from Scripture alone.

Second, I think that if you are looking for some sort of essential link between the acceptance of slavery and the belief in the doctrine of the Trinity in hopes of thereby scoring points against Trinitarians, that (1) your efforts may be successful, (2) ill-advised. First, your efforts may be successful in the way that any ad hominem attack may garner certain desired effects in an environment well-disposed to applaud your loathing of slavery (much as Michael Moore's piece of muck-raking Bush-bashing in Farenheit 911 elicited hysterical cheers from the Kerry-Edwards grandstands). But I think the approach ill-
advised precisely because it fails to rise above the level of a
circumstantial ad hominem, which means it doesn't rise to the level of an actual argument.

Third, my own opinion about slavery is that it lies somewhere in a vicinity similar to that of the death penalty. There are good reasons for opposing it, even if, strictly speaking, one finds no categorial contemnation of it (and even sometimes an apparent indifference to it, if not support for it) in Scripture. I've read the analyses of the issue by the conservative Presbyterian, John Murray, and other like him; and the primary thing I would say here is that one must be extremely careful on this subject not to assume that we know what is meant by "slavery" in the context of every author who addresses it-- any more than, say, Lutherans ought to commonly assume that they know what an "indulgence" is when they popularly make jokes about indulgences. "Slavery" covers a wide spectrum of practices from the cruelest and most morally repugnant treatment of human beings to mild forms of servitude that are still common practice, not only in homes of British nobility who still typically have servants, but among Beverly Hills Democrats who hire illegal immigrants to serve as their children's "nannies" in exchange for some dollars under the table. Not all of Giles' "especial characteristics that define slavery" define ALL slavery. For example, Giles says that "slaves are considered to be the property of other humans" and that a "slave is the 'commodity' of
another human being." John Murray, on the other hand, writes: "It is not to be concluded ... that slavery involves the property of man in man.... The fact appears to be, rather, that slavery is the property of man in the LABOUR of another." (Principles of Conduct, p. 97).

Fourth, although the Catholic Church has a record of staunch opposition to the institution of chattel slavery, again, I doubt whether the case against this form of slavery can be made readily from Scripture alone. Rather, a solid case can be made only on the basis of Sacred Tradition and natural law (though some Catholics have also tried to supplement their arguments from Scripture). Excellent discussions of the issue can be found in the Catholic Encyclopedia articles on "Slavery and Christianity" (excellent historical overview) and "Ethical aspect of slavery" (a moral/theological analysis).