QUA is ‘in so far as’. This word is known among philosophy scholars because Aristoteles (Aristotle) uses it in describing his work known as Metaphysics. In fact, he never uses the word ‘metaphysics’ and describes his subject matter in several other ways as well. Firstly, he defines it as the study of ‘being qua being’. Secondly, as ‘first philosophy’. Thirdly, as ‘wisdom’. Also as ‘theology’.
Aristoteles’ Greek word has been Latinized as <qua> and it means roughly ‘in so far as’ or ‘under the aspect’. Then, as an example, a study of “the sky qua colors” would be a study of the sky solely under the colors’ aspects. It means that such a study would not include the astronomical aspects nor the chemical one or the physical one. Therefore, we can say that the main subject of Metaphysics is ‘being qua being’ or ‘being insofar as it is being’.
<Qua> is ‘in so far as’. Hence the work of Aristoteles investigates what can be asserted about ‘being’ itself. It means “what can be said of any being insofar as it is” and not because of any special qualities it has. Also, the same book covers different kinds of causation, form and matter, the existence of mathematical objects, and a prime-mover God.
Three questions are at the core of Metaphysics. What is existence, what kind of things do exist in the world? How can things continue to exist notwithstanding their changes? How can this world be understood? Clearly, Aristoteles’ effort in Methapysics is to elaborate about the common structure behind the changes in natural world. At his time, the theories of Herakleitos ho Ephesios (Heraclitus) and Parmenides are widespread. The first emphasizes the changing nature of apparent reality. The second argues that we can reach conclusions with only the reason.