Aquinas regards metaphysics as the study of being qua being, which is to say, the study of being as such (ens inquantum ens). Everything that exists can obviously be studied and, accordingly, made the subject of a science. Beings insofar as they are living are the subject of biology, while beings insofar as they are in motion are the subject matter of physics, to name two examples of disciplines that most moderns would recognize as legitimate sciences. Contemporary readers might