Here’s a passage that I liked from Newbigin. I replaced that pesky "m-word" with "long-term tour-guide." Hope you figure out what he’s talking about:

Traditions of rationality are embodied in languages. A rival tradition cannot become a serious threat to the adherents of an existing tradition unless these latter are able to learn the language in which the rival tradition is embodied. One may learn a language at two levels. It may be simply a second language: the learner continues to think and reason in the native language, but learns to find words and phrases in the second language which correspond as closely as possible to those of the first language. But one may acquire what MacIntyre calls a "second first language," a language which is learned in the same way that a child learns to use the native tongue. A [long-term tour guide] or an anthropologist who really hopes to understand and enter into the adopted culture will not do so by trying to learn the language in the way a tourist uses a phrasebook or a dictionary. It must be learned in the way a child learns to speak, not by finding words to match one’s existing stock, but by learning to think and speak in the way the people of the country do. A person who seeks to learn it in that way quickly discovers that the two languages are mutually translatable only to a very limited extent. Words used in two languages to denote the same kinds of things have very different meanings because of the different roles that these things play in the two cultures…

The English [long-term tour guide] can feel the force and beauty of the worldview embodied in the Tamil poetry. He can set it beside the worldview in which as an English person he has been trained and the biblical worldview in which he seeks to grow. There is thus an internal dialogue into which the question at stake is: "Which is more adequate for grasping and coping with reality with which all human beings are faced?" This is a dialogue about truth. In this dialogue the two traditions of rationality are compared with one another in respect of their adequacy to the realities with which all human beings have to deal. And, obviously, this internal dialogue is the necessary precondition for the external dialogue which is at the center of a [long-term tour guide’s] proper concern. Although the two ways of reasoning are not mutually translatable except to a limited degree, that does not mean that they cannot be compared in respect of their adequacy to enable human beings to know and cope with reality.

from Mr. Newbigin’s The Gospel in a Pluralist Society