Do numbers exist? Glad to be on this forum.
Forgive any apparent crude or unintelligible thoughts. As to the question of whether numbers exist:
Who can question whether number exists in the mind? Whether they have concreteness is simply to say, 'do they exist in reality as they exist in mind?' Obviously not. Temporal construction is such that inequality defines its nature. Equality, on the other hand, can only be outside of temporality. One might say: 'equality can only exist eternally.'
The question then arises, 'what is the nature of number?' Conjecturally, one might say, number is a series of equal values (quantity). Hence, Pythagoras' and other ancient mathematicians' inclination to render number as equal, whole values. If this is an accurate description of number, then it follows, the concept of number is tied to the idea of a 'unity' value (unit measure).
The question can then be asked, 'where does the concept of 'unity' come from? Again, conjecturally speaking, unity may only be understood as an eternal concept. So, the question of whether number exists, is tied to the answer to the question of whether eternity exists.