Even from a methodological point of view, references to Catholic Christianity are far from straightforward. Such references are possible only if we have already referred to Christianity in general, for it is only within the genus ‘Christianity’ that we can deal meaningfully with the Catholic component in the sense of a specific difference. It is, however, certainly possible to dispute this, for there are those who believe, specifically with respect to Christianity in general, that the specific activities in which the denominations are engaged are underpinned by a fundamental hermeneutic difference, such as the Protestant principle.

We may attempt to escape this difficulty in a number of ways. We may attempt to draw up basic models of the individual world religions and, within Christianity for example, outline the denominational variations. This may be done, as we often find today, in a way understandable to the general reader. It is not unusual for it to be done in a fairly vulgar fashion. A more sophisticated variant is the attempt – with more stringent philosophical means, and above all with the aid of the phenomenology of religion – to convey the specific ways in which the Christian faith has been elaborated. Here again, differing emphases are to be found, because there are of course very different forms and types of philosophy of religion, not to mention predominantly sociological or psychological foci. While scholars have generally been wary of producing denomination-specific accounts, some respectable attempts have been made in this direction.