Elizabeth Anscombe, answered from the texts and cited to the page.
Catholic moral theology grounds the philosophical positions, and the philosophical positions are defended by argument that does not require the prior authority of Church teaching. The two-mode structure is in the texts: when addressing Catholic audiences (Hawkesyard, the Linacre Centre, the Catholic Truth Society), the arguments presuppose the authority of revelation and the Church; when addressing philosophical audiences (Oxford, Cambridge, Mind, Analysis, Philosophy), the arguments are philosophical and do not presuppose Catholic doctrine.
Both modes are mine. The opposition to contraception, the defense of transubstantiation, the absolutism on the killing of innocents, the just-war framework, the philosophy of faith — these are defended in both modes, by different arguments suited to the audience. The substance is not different. To read the philosophy as detachable from the Catholicism — "her ethics without her religion" — is to miss that the philosophy is the Catholicism, worked out in philosophical form, and that the Catholicism is the philosophy, lived out in religious form. The two-mode distinction is methodological, not substantive.12
They all contribute to a rounded understanding of her work. Human Life, Action and Ethics. Essays by G E M Anscombe, edited by Mary Geach & Luke Gormally (Exeter & Charlottesville, VA: Imprint Academic, 2005). Professor Sir Michael Dummett, in The Tablet 9 July 2005.Faith in a Hard Ground, [1]–[4]
I remember nobody at all asking: 'Well, of course, human beings have always had morality, but the question is what morality?' The suggestion that you should ask 'what morality?' was not made in any discussion that I heard. It always seemed to be assumed that if you could have morality, it would be...Faith in a Hard Ground, pp. 113–114
The most polemically contested aspect of her work, especially since the secular reception has often tried to detach her ethics and philosophy of action from her religious commitments. The Catholic philosophical tradition (Finnis, Grisez, Haldane) treats the two as continuous and develops them together. The secular readers (Foot, who was an atheist; MacIntyre in his earlier After Virtue period before his later Catholic turn; most contemporary virtue ethicists) have taken up parts of the ethics without the religious framework. She herself was clear throughout her writing on religion that the framework was integrated, and the late papers in Faith in a Hard Ground make the integration explicit.