Those things are said to be other in kind whose ultimate substratum is different, and which are not analysed the one into the other nor both into the same thing (e.g. form and matter are different in kind); and things which belong to different categories of being; for some of the things that are said to be signify essence, others a quality, others the other categories we have before distinguished; these also are not analysed either into one another or into some one thing.