A science of being qua being considers features on the same level of generality as being. The "qua" phrase should be taken in the commensurately universal sense of Posterior Analytics I.4. I give truth conditions for Aristotle's "qua" propositions. Aristotle takes the science of being qua being to investigate attributes of being holding qua being: being and unity and their contraries. Also it looks for principles common to all beings, like the principle of non-contradiction. Again, it investigates what is required for all beings to exist: namely individual substances , as well have what their fundamental principles are. Finally it considers other ultimate causes of being, like God, Who is also the preeminent case of being.