I've been following with some interest the discussion at Sacramentum Vitae regarding the Filioque controversy. Much of it is familiar ground, but the dialectic is still fascinating. (I've posted on this controversy myself a few times; just use the blog search to find it all.)
It's tempting, sometimes, to look upon debates of this kind as threatening, somehow, to our Christian identity. The reason for this, I suppose, is that we all tend to prefer concord to discord, harmony to cacophony. The temptation to worry about such things should be resisted, however. When the philosophical writings of Aristotle were rediscovered in the West during the thirteenth century, they became extremely popular subjects for discussion among certain teachers at the universities of Paris and Oxford. In some ways, Aristotelian philosophical perspectives could be viewed as threatening to Christian doctrine, provided that one antecedently adopts certain philosophical starting points that are incompatible with Aristotelianism. In 1210 the provincial synod of Sens attempted to put a stop to whatever pernicious influence Aristotelianism might have upon the nascent clerics at Paris by forbidding the Masters of that institution from reading any texts by Aristotle, either in public or in private, thus forbidding also the teaching of said texts. The ban was repeated in 1215, and in 1231 Pope Gregory IX promulgated a bull that extended the ban, in a modified form, to other universities. (For some reason the university at Toulouse was immune from the ban, until Pope Innocent IV extended it to include all of Christendom in 1245.)
Papal pronouncements in the thirteenth century appear to have been viewed with the same care and respect that they are accorded these days in institutions of higher learning: by the 1250s the ban was being ignored everywhere, especially in Paris and Oxford. Bonaventure, in his capacity as minister general to the Franciscan order, called upon Etienne Tempier, bishop of Paris, to issue a condemnation of certain Aristotelian theses. In 1270 and again in 1277 he issued the famous condemnations that had the effect, in the end, of putting Saint Thomas Aquinas, a thoroughgoing Aristotelian (and a, ahem, Dominican), on the index of forbidden teachers. This situation was not changed until Thomas's canonization in 1325.
For roughly a century, then, some of the most fundamentally important philosophical perspectives in history were banned from institutions of Christian education, in spite of the fact that many of these perspectives were not merely consistent with Christian teaching, but were actually quite effectively deployed, by Aquinas and others, in the defense of Christian belief. Looking back on this situation from a distance of over 700 years, one can simply scratch one's head in wonderment over the thoughtlessness of certain kinds of partisanship, but at the time, to those who found Aristotle's texts brimming with stimulating and fertile ideas, the ban must have seemed not merely frustrating but positively maddening. In the midst of the controversy itself the disparate sides must have experienced varying degrees of fear and loathing for one another, and yet, in the end, the whole thing was settled amicably and has remained relatively irenic for seven centuries, a sevenfold increase over the amount of time spent squabbling about things.
Some may wish to suggest that the controversy over the Filioque is of an entirely different order than disagreements over curricula that are largely internal to institutions of higher learning and, hence, is not about to go away any time soon. On the one hand, there is some truth to this: after a millennium of argument, there are still some folks who regard the controversy as a point of schism between East and West. On the other hand, the relative importance of the issue with respect to division-making power can be seen in the fact that the version of the Creed used in Uniate liturgies omits the Filioque with the Vatican's blessing. One thing that is about as clear as anything from the posts and comments at Sacramentum Vitae is the fact that the issue turns on various philosophical notions, including cause, unity, identity, and other inheritances from the Neoplatonic and Peripatetic philosophical traditions. As the condemnations of 1270 and 1277 illustrated so nicely, philosophical conventions come and go, sometimes with alarming frequency, sometimes only very slowly. The long view seeks to go beyond theological analysis, which is always metaphorical and analogical at best, and hit upon the deposit of faith which is the same for everyone at all times and places. This task, of course, can be extremely difficult, and it goes without saying that it cannot be accomplished in a conceptual vacuum: philosophical machinery will necessarily be deployed, whether intentionally or not. What ought to be of interest is not the machinery deployed, however, but the faith displayed. If the dialog between opposing parties is a cooperative search for the truth, then charity demands that we wait until both sides have had their say. In this there is, perhaps, some small difference between the words being exchanged at Sacramentum Vitae and the condemnations of 1270 and 1277.
C. S. Lewis, famously, tried to do an end-run around problems such as the Filioque controversy by searching what he thought of as "the tradition" for those elements of belief that, in his judgment, stood the test of the so-called "Vincentian Canon". The result was his Mere Christianity, drawn from a series of radio addresses and constituting a kind of curious attempt at a non-denominational Credo. While such palliatives are sometimes attractive to certain sorts of minds, they are rarely as satisfying as the quest for deeper understanding that animates the differences of theological opinion that they mask. (In this respect it is rather surprising that Lewis, one of the most brilliant minds of his generation, adopted such an approach.) Indeed, in the absence of difference and variation it is not clear whether our understanding could advance at all beyond the truths that we are spoon-fed from the Gospels themselves. Everyone, Greek as well as Latin, knows that the Gospel of St John tells us that the Son "sends" the Holy Spirit; the dispute is not over that fact, but over the meaning and interpretation of that fact and how it is to be interpolated among the other facts handed us by the Gospels. To say with the "mere Christian" that all we need know is that the Son "sends" the Spirit and no more, is to sow the seeds of heterodoxy, since it leaves to individual judgment what, precisely, the upshot of "sending the Holy Spirit" is to be taken to be. It will not do to say, "Just don't think about what the 'upshot' of our faith is to be taken to be, just endorse the facts as we have them." That is like telling a teenage boy "Our cable package came with the Playboy channel, but don't you dare turn it on, even when I'm not at home!" The Filioque controversy arose in the first place as a consequence of localized attempts to put a stop to Spanish monarchianism (a heretical version that denied the subsistence of the Son, not the orthodox version that says that the Father is the only arkhê, "principle" or "source"). In localized liturgies where there was a danger of the heterodoxy, the Filioque was inserted into the Creed to make the Son's subsistence clear (lex orandi, after all, is lex credendi). This local change was later endorsed by Rome, even though the threat of heterodoxy was not a universal one, but that Rome permitted the change in the liturgy at all was part of what angered the Greeks. Or at least some of them: Theophylact of Ochrid noted that the Latins did not have the rich theological vocabulary available to the Greeks, and in particular they had only one word for "procession" whereas in Greek there were four different verbs to indicate four different ways in which it was possible for one thing to "be from" another (ekporeuesthai, khorêgeisthai, metadidosthai, and pempesthai).
Theophylact was extremely patient about the inability of the Latin language to do justice to the finial theological nuances of the doctrine of the Trinity, far more so than most Greek theologians of his day, who took advantage of theological excuses to promote their own anti-Latin Church polity. In his view it was important to allow for the particularities of local practices in the various Churches, especially in the East (he appealed to the case of the Bulgarian Church to illustrate how even in the East it is essential to insure the understanding of theological terms by the lay members of the community) but also, of course, in the Latin West, and many of the differences between East and West he ascribed to cultural differences that were due ultimately to differences in language and custom. Such things were quite permissible, in his view. He drew the line, however, when it came to matters that had been settled by the decision of an Ecumenical Council, and the text of the Creed fell under this rubric. With the insertion of the Filioque clause the Latin West had gone too far, in his view.
And there, for the most part, is where things stand to this day. By now, of course, Western theologians have had plenty of time to absorb the nuances of meaning present in the verbs ekporeuesthai, khorêgeisthai, metadidosthai, and pempesthai, yet they continue to maintain the validity of the insertion of the Filioque clause into the Creed, and the Greeks continue to object. The dispute over the Filioque has been called trivial by Kallistos Ware, but others are quick to point out that it is but the tip of the iceberg separating East from West. Even if this is true, however, it must be admitted that even a thousand years is not very long in comparison with eternity, and I suspect that the long view will see even this dispute in much the same way that we now see the condemnations of the thirteenth century.