Monad, Dyad, Circle, Ellipse

It is unclear if Leibniz is aware of the historical precedent of his use of the term Monad.  That is Pythagoras', and it is the name of his diety, the simple and original entity from which all else follows, including the Dyad, his term for Matter.  So, Leibniz' use is perhaps doubly ironic--the existence in his system of a plurality of Monads is contrary both to what the term connotes, as well as to the Monism of his ancient predecessor.  Now, the Pythagoreans represent the Monad as a point within a circle.  So, the irony in their case is that these pioneers of Geometry seem unaware that a Circle is a special case of an Ellipse, and, specifically, of a figure with two foci.  In other words, the image of an Ellipse with two foci could represent the Dyad, which therefore precedes the Monad.  Indeed, the reduction of an Ellipse to a Circle could represent one of the most ancient of philosophical endeavors--the attempt by a complex entity to posit the prior existence of a simple entity from which it is derived.