If the early philosophical links with the West were Greek, the first mathematical links were Italian. The development of the Concept of Zero, its Western intellectual foundations, begin with Fibonacci [1170-1240; ‘The Greatest Western Mathematician of the Middle Period’] and sealed later by Guiseppe Peano [1858-1932].
The latest subscribed research into Number Theory goes back less than 150 years with the formal conceptualization of the Symbol ‘0’ by Guiseppe Peano in his five famous postulates. [The first postulate reads: ‘Zero is a natural number’].
The Mathematician’s notion of Unity or Wholeness is the idea of the Mathematical Set. [In the wonder-world of the Self-Loop, the word with the most number of posted definitions the last time I checked seems to be the word ‘Set’, as in Mathematical Set, which is another word for ‘Definition’.]
The problem becomes intractable once the investigators take the notion of ‘Unity’ to its necessary limit. And that required immersion into Set Theory [again, Peano pioneered its early application]. And in Set Theory they hit head-on into the Self-Loop.
The Self-Eating Expression comes alive from the shadows anytime something is used on itself, anytime we are wading, knowingly or otherwise, into the swamp of the Self-Loop.
The single tripper-upper? The notion of Self-Reference [recursion, repetition, reflection and numerous variants].