In his great book The Idea of the Holy, R. Otto analysed what he regarded as the ‘a priori’ category of holiness. Holiness properly belongs, he argues, to the sphere of religion. The word ‘is, indeed, applied by transference to another sphere—that of ethics—but it is not itself derived from this … if the ethical element was present at all at any rate it was not original and never constituted the whole meaning of the word’. As Israelite religion develops, the ethical element gains prominence ‘The venerable religion of Moses marks the beginning of a process which from that point onwards proceeds with ever-increasing momentum, by which the numinous is throughout rationalised and moralised, i.e. charged with ethical import, until it becomes the “holy” in the fullest sense of the word. The culmination of the process is found in the Prophets and in the Gospels.’