The term "Metaphysics" (ta meta ta physika) was introduced by Andronicus of Rhodes to classify a collection of texts of the Corpus Aristotelicum that concerned those matters that did not have place in the books of Physics.
Metaphysics refers to the branch of philosophy that studies the first causes, principles and origins of all things. Causes, determinations, reasons and respective foundations are approached within Metaphysics.
As the science of the first causes, principles and origins of all existing things, Metaphysics is an archeology (arche). As science of the being as being it is an ontology. Metaphysics is irreducibly a philosophical concept about the first causes, principles and origins of all existing things.
One must stress that we are not addressing anything that is outside the Cosmos. Indeed, every physical object is also a metaphysical object, in its connection with its origin and foundation.
In this way, as a methodological criterion, Metaphysics concerns the foundation of all the existing things as such. It is, thus, about inquiring in the things themselves, that which, in them, is present as their originary and originating condition, which means that a metaphysical inquiry demands that one questions the foundation itself, that, as such, is present in the things, themselves, as that which maintains them and sustains them as entities, identities and integrities existent and subsistent, in themselves and by themselves.
The foundation is a principle of reason and, thus, of proportion, pattern, number. As Leibniz stated “nihil est sine ratione”. The foundation is incorporated in the nature of the things themselves, as their possibility as existent things, in themselves and by themselves (autonomy).
That which Metaphysics strives for is to find not only that proportion/symmetry/order but that which preceded it. It is no longer, in this last case, about inquiring the being, entity or identity, but about questioning the foundation itself, and, thus, searching for the originating principle of the foundation itself, as its existing potential (Aristotle) anteriority, that is, what ordering principle (number, pattern, order) underlies the foundation itself as an existent foundation of each individuated existent.
Whenever a cosmologist is addressing the first causes, principles and origin of the Cosmos/Order and the entanglement that we call Universe, inquiring about the nature of the laws of physics, or upon the foundations of physics he/she is in a metaphysical inquiry, having to make an effort to interpret that which exists in the Cosmos outside his/her logocentrically conventioned closed mental models and Sapiens' logics, which, in many cases, and in an abusive way, are called metaphysical models, putting into evidence a total lack of knowledge of the notion of Metaphysics itself.