Which case, and why?

You have asked me, ʿAbd Allāh the jurist al-Maʿṣirī (may God grant you happiness), to compose for you a treatise that sets out a clear account of love (ʿishq), and to do so concisely. I have agreed to your request, seeking to please you and to fulfil your wish; may I never cease to pursue good things. I have divided my treatise to you into seven chapters. The first concerns how the power of love pervades each one of the beings. The second concerns the existence of love in the simple substances that are not alive. The third concerns the existence of love in existing things that possess a nutritive faculty, with respect to those nutritive faculties. The fourth concerns the existence of love in animal substances insofar as they possess the animal faculty. The fifth concerns the love of the refined and of young men of chivalry for handsome faces. The sixth concerns the love of the divine souls. The seventh is the conclusion of the chapters.