Perfect Being Theology


In this topic, we will look at the method for philosophizing about the nature of God usually called “perfect being theology”. Perfect being theology is a way of reasoning about God’s nature by reflecting on what follows about God if we define Him as the best being which could possibly exist, and we reflect on our knowledge of right from wrong, better from worse. The method of perfect being theology is usually seen as described explicitly for the first time by St Anselm of Canterbury in the Middle Ages: the philosopher responsible for the first version of the ‘ontological argument’ for God’s existence, which is itself a piece of perfect being theology. But arguments that God must be some way, rather than another, because He is perfect are at least as old as Western philosophy. The sacred texts of the Western monotheistic, or ‘Abrahamic’ religions, Judaism, Christianity, and Islam, all describe God in a way which led theologians in these traditions to use perfect being theology when thinking about God. Perfect being theology holds out the promise of a systematic method for investigating God’s nature and existence which does not rely on ‘faith’ or ‘revelation’.


Doubts about the meaningfulness of claims about God’s nature, and the objectivity of right and wrong, made popular in the first half of the twentieth century were largely overcome in the latter half. One result is that in contemporary philosophy of religion there has been a huge revival of perfect being theology. But even if we have knowledge about morality, can and should we attempt to use this knowledge to investigate the nature of God? Or are there good reasons for theologians to be skeptical or wary of perfect being theology? How successful has perfect being theology been in the past, and what are its prospects?


Work through each activity in turn, answering the questions at the end of each PDF. The ‘Useful Links’ section links to two online editions of Anselm’s Proslogion, which you can use to help you with the tasks.

Contemporary (and some slightly older) philosophical articles and books are referenced in the text using footnotes. You do not need to have access to them for the purposes of these exercises, but a lot of progress in philosophy takes the form of contemporary writers articulating more explicitly and precisely what is implied in the work of their predecessors, so it’s good to be aware of and give credit to contemporary thinkers. Ancient and medieval sources are cited in the footnotes. Often they appear with the name of the source or an abbreviated version and then followed by some numbers, usually chapters or rather than page numbers. This means that you can find that reference regardless of which edition you are using.

The Proslogion can be found in PDF here and in HTML here.

Video Resource

Video Resource

Resource activities

What is Perfect Being Theology?

In this section, we look at St Anselm’s articulation of the method for philosophizing about God now called ‘perfect being theology’, starting with his famous definition for God in the Proslogion. 


Reasons For and Against Perfect Being Theology

Here we consider two long-standing objections to using perfect being theology.


God's Perfections

Pretty much since the dawn of Western philosophy, perfect being arguments have been made.


Is There A Perfect Being?

Perfect being theology is a way of thinking about God which follows from the assumption that God is a perfect being – the best being possible.


Reflective questions

To answer and record these questions you will need to have an account and be logged in.

Task 1

What are the key arguments, concepts, points contained within it?

Task 2

What are you struggling to understand?

What could you do to improve your understanding of these concepts/terminology etc.?

Task 3

What further questions has this resource raised for you?

What else are you keen to discover about this topic and how could you go about learning more?

Can you make any links between this topic and your prior knowledge or school studies?

Help us evaluate this resource

Your feedback is very important to us. Please complete a short questionnaire.


Further reading

  • The method of perfect being theology

    This University of Notre Dame paper shows some of the methodology for thinking about this question. The maths is a bit tricky, but if you can get past that and look at what the author is trying to do it can still be useful.