MARRIED to a deacon, I am hardly unbiased, so ignore my judgement. I was less than enthusiastic at the Roman Church ’s position cited in ND in February. (Q: Is it possible to separate the diaconate of women from the priesthood of women? Müller: No, because of the unity of the sacrament of orders …)

The argument, as briefly elaborated in the rest of the short article, was nevertheless incisive, uncomplicated and above all logical. Logical, that is the point. It adds considerable power to the argument; indeed it is the power of the argument. It is not unlike the classic Socratic syllogism. The sacrament is one. Therefore it cannot be divided. Therefore if women are excluded from one part of the sacrament, they must be excluded from any other part. As Müller put it, ‘it is obvious ’.

The Anglican Province of Southern Africa accepted the principle of women bishops on the same basis. If there are women priests, then, it declared, ‘it follows logically ’ there can be women bishops. Its provincial synod passed the resolution in a matter of fifteen minutes in 1995.

So that ’s all right then? It works for both sides? No. It works for neither. It may surprise theologians, but philosophers spend hours, years, a lifetime arguing the nature of logic. It is not as easy as its users too often suppose. Deductive reasoning in particular ought to be treated with more respect.

Let me give an example. Do you know of that cruel heresy of Double Predestination? It arose in Calvinist thought because ‘it follows logically ’ from the relatively plain and unadorned doctrine of (single) predestination. In the Dutch Reformed Church, it became the foundation for the theological justification of apartheid. It is perhaps the nastiest of all the heresies, and should be more widely studied, for it carries a stark warning against too simplistic a use of deduction.

Logic is vital. But its very power can make our use of it lazy. As Christians we ought to be more careful. As far back as the second century, Tertullian warned that if we rely too much on logic, we shall be forced to jettison the doctrine of the Incarnation. Have not some done just that?