two rival accounts of dueling traditions

One thing really interesting about the MacIntyrean account of the history of ethics is how he uses a lot of modern, Kuhnian terminology on an Hegelian framework. This may lead some to suspect that Kuhn's account in The Structure of Scientific Revolutions is also Hegelian or semi-Hegelian. It is not.

The Kuhnian model is, in outline, very simple:

1. First, we have a "normal science". The classic example is Newtonian physics.
2. Next, we have anomalies which are difficult to account for within the boundaries of the normal science. These often lead to complicated resolutions, like epicycles in the Ptolemaic cosmology.
3. Eventually, we have one or more competing models which seek to usurp the current paradigm and better account for its anomalies. These models are incommensurable with the former model, and each other.
4. Finally, a "paradigm shift" occurs, which eventually is resolved into a new period of normal science.

Note the clear lack of antithesis and synthesis. The former model is replaced. Darwinian evolution took no prisoners with the Lamarckian*. The only reason Newtonian mechanics are still around is because they're a lot easier to learn and work well enough for nearly all human endeavors. Classical uniformitarianism was left behind after the (rather quick, and some say inspired by Kuhn) paradigm shift to plate tectonics.

Compare this also to Newman. Thesis and antithesis are not there, but his picture of the church often feels like the late-Hegelian state channeling the world-spirit. That certain Catholics, in light of Vatican I, have reread Newman in the voice of Hegel–"The Pope is the Holy Spirit on horseback!"–isn't shocking.

Now, Kuhn's work was a philosophy of the history of science. (It was not a philosophy of science, as it was unconcerned with a number of the classic epistemic problems in that branch. Professors who teach it as being a competitor to other philosophies of science, or worse yet, as being "postmodern", be warned.) That means that it is not going to fit well for other forms of human endeavors, like ethics. Even in science, it is not an excellent description for history as we have it, but very useful for coming to understand it, and to critique our conditioned notions of it.

Using the terminology was smart, and in many ways, MacIntyre's accounts of ethical traditions really resemble Kuhnian normal sciences. It also serves to couch the Hegelianism in trendier terminology.

I complained of the Hegelian portion of his model in trying to understand Aquinas: Aristotelian thesis, Augustinian antithesis, Thomist synthesis. In a quasi-Kuhnian interpretation of Aquinas, you could have Augustinian normal philosophy interrupted by an Averroist exploitation of its weakness, which is then followed by a Thomist model which usurps them all and becomes a new normal philosophy. (Obviously, that did not happen, but this is philosophy of history, and we shan't let facts disturb us long.)

This is also a poor description of what was happening.

Rather, the Church has seemed to have had a long and successful trial of straining babies from bathwater when it comes to its encounters with philosophy. We see it in late antiquity with (primarily) Neoplatonism and Stoicism. The debts to the former fall primarily in metaphysics and terminology. The debts to the latter in areas of "practical wisdom" like morals and the law.

But this was not synthesis. It was a willingness to take what was good from the world around it, without undue fear of it (we cannot grant it power). It did not only happen then, both the Greek and then the Latin worlds absorbed fruitfully Neoplatonic revivals on their soil in the late Middle Ages, though in markedly different ways.

This does not solve the essential MacIntyrean problem of incommensurability between rival traditions. I think this is a real problem today, but it does not map to history very well. While issues such as Sophism opposed to Socratic/Platonic philosophy were ones of deep conflict, there is also evidence there of a shared pre-philosophic foundation that made discussion possible. MacIntyre's account of this conflict, which focuses on an idea that they were divided by favoring, respectively, goods of effectiveness or the goods of excellence (I cannot remember if he uses that precise shorthand) says more about MacIntyre's model than Athenians. (Interestingly, another comment about the concept of rhetoric vs the concept of dialectic is introduced only as an aside.)

The question of incommensurability, however, may just be a question of pride, and confusion regarding the role of philosophy. We've held philosophy to strange standards, which have likely been further reinforced by what MacIntyre (rightly) decries as its professionalization. The good thing about incommensurability is that, properly considered, it can lead us back to some epistemic humility.

*This is why it is somewhat amusing when we talk about "neo-Lamarckian" evolution, such as with ideas that dormant genes may be "activated" in offspring due to environmental pressures on the parent(s). This is only remotely related to Lamarck, and the fact that we can call it that shows that the steam has gone out of the prior debate.