The usual subdivisions of these two general parts of philosophy were as follows. Theoretica (or _Theorica_) was divided into (1) Physics, or _scientia naturalis_, (2) Mathematics, and (3) Metaphysics or Theology, or _divina scientia_, as it might be called. Physics and Mathematics were again divided into more special sciences. _Practica_ was divided commonly into Ethics, Economics, Politics, or into Ethics and _Artes mechanicae_. There was a difference of opinion as to what to do with Logic. It had, to be sure, its position in the current Trivium, along with grammar and rhetoric. But this was merely current, and might not approve itself on deeper reflection. Gundissalinus speaks of three propaedeutic sciences, the _scientiae eloquentiae_, grammar, poetics, and rhetoric, and then puts Logic after them as a _scientia media_ between these primary educational matters and philosophy, _i.e._ the whole range of knowledge, theoretical and practical. Again, over against _philosophia realis_, which contains both the _theoretica_ (or _speculativa_) and the _practica_, Thomas Aquinas sets the _philosophia rationalis_, or logic; and Richard Kilwardby opposes _logica_, the _scientia rationalis_, to _practica_, in his division.[437] The last-named philosopher was the pupil and then the hostile critic of Aquinas, and also became Archbishop of Canterbury. He was the author of a careful and elaborate classification of the parts of philosophy, entitled _De ortu et divisione philosophiae_.[438] In it, following the broad distinction between _res divinae_ and _res humanae_, Kilwardby divides philosophy into _speculativa_ and _practica_. _Speculativa_ is divided into _naturalis_ (physics), _mathematica_, and _divina_ (metaphysics). He does not divide the first and third of these; but he divides _mathematica_ into those sciences which treat of quantity in continuity and separation respectively (_quantitas continua_ and _quantitas discreta_). The former embrace geometry, astronomy and astrology, and perspective; the latter, music and arithmetic. _Practica_, which is concerned with _res humanae_, is divided into _activa_ and _sermocinalis_: because _res humanae_ consist either of _operationes_ or _locutiones_. The _activa_ embraces Ethics and mechanics; the _scientia sermocinalis_ embraces grammar, logic, and rhetoric. Such are Kilwardby’s bare captions; his treatise lengthily treats of the interrelations of these various branches of knowledge.