Wallace Stevens' poetry is sometimes orotund, coinciding with the general repleteness & rotundity of WS, as in similar modus William Shakespeare offers a mighty graceful Globe;

and as WS oftentimes mentions the poetry to be found in philosophers,

so, I recommend Nicolaus Cusanus, or Nicholas of Cusa, whose interest in roundness surpasseth all others;

quotes to follow -

Therefore the edge of the world is not composed of points, but its edge
 is roundness [rotunditas], which consists in one point. 

 
Roundness cannot be composed out of points for, since a point is indivisible 
and does not have quantity or parts or a front and back or other differences,
it cannot be joined to another point.

 
Only length and width can be seen.  But in roundness nothing is long or wide
or straight.  Roundness is a kind of circumference, a certain convexity led
around from point to point whose top is everywhere.  And its top is the atom,
invisible because of its tininess.

 
The round world is not that roundness itself than which no roundness can be
greater, but that roundness than which nothing can actually be greater.
Absolute roundness is not of the nature of the roundness of the world, but is its
cause and exemplar; the absolute roundness of which the roundness of the world is
the image.  I see the image of eternity in a circle where there is neither a beginning
nor an end since there is no point in which it would be the beginning rather than
the end.  [italics mine]

Listen to this subtlety :

Moreover unity is more perfect and simple to the degree that it is more uniting.
Hence the Trinity, which is one in such a way that it is also in three persons, each of
which is one, is more perfect.  And unity would not be most perfect in any other way.

similarly :

Consequently you must open up the gaze of your mind, and you will see that God
is in all multitude because he is in the number one, and in every magnitude because he
is in the point.  From this it is established that divine simplicity is more subtle than the
number one and the point which gives the unfolding power of multitude and magnitude.
Hence God is a greater enfolding power than that enfolding power of the number one 
or of a point.

Edward J. Butterworth (rotund moniker) has a perfectly succinct essay in the book Nicholas of Cusa in Search of God and Wisdom (Brill, 1991), clarifying these concepts & relating them to the earlier Alan of Lille, who wrote : Deus est spaera intelligibilis, cuius centrum ubique, circumferentia nusquam. Moreover, Lille :

The creature is called the center because, as time, compared to eternity, is thought
a fleeting motion, so the creature, compared to God, is a central point.  Therefore, the
immensity of God is said to be the circumference, because it disposes all things in
such a way that it encompasses them and enfolds all things within its immensity.

It's possible to find only word games & rhetorical sleight of hand here. But not if you take into account Cusanus' commitment to the (negative-theological) absolute otherness of God. Mathematical terms are applied to simplicity, while concrete (physical) terms are applied to multiplicity (as in Alan of Lille). Yet otherness and the physical universe are joined, related to one another, by shared geometrical terms & analogies (in a relation of material actuality, on the one hand, and ineffable, invisible & infinite (yet intelligible) perfection, on the other). Alan of Lille's "Intelligible Sphere".

Leading (Butterworth illuminates, partly via Einstein) (& around again) to Cusanus' limpid, rotund contradiction :

Therefore the edge of the world is not composed of points,
but its edge is roundness, which consists in one point.

(All Cusanus quotes from
De Ludo Globi (The Game of Spheres))

what's that Dickinson line? "My circuit is circumference" [?]