Topics are so aery a thing that you are only ever ‘informed about’ them, but as for ‘subjects’: only they can ‘inform’ one. As so often, this question attracted me not because I have anything substantial to say about it in answer but because so much of its terminology has had importance to me in … More Topics are so aery a thing that you are only ever ‘informed about’ them, but as for ‘subjects’: only they can ‘inform’ one.