&gt; <i>Without a mind to understand, interpret, and define mathematics, does it exist? </i><p>Unquestioningly so. For instance, there is a number 2 and a number pi which are not caused by thinking. Beings which evolve on separate planets (or whatever) in separate universes have to to come to the conclusion that the ratio between the diameter and circumference of a circle is a certain number. Those numbers will be found to agree, though there is no causal link between the two.   You can define what constitutes a circle, and define the question of the ratio of its parts, but you don&#x27;t get to define pi.<p>Or, if you define &quot;composite&quot; and &quot;prime&quot;, you don&#x27;t get to decide which integers are one or the other, or facts like that two is the smallest prime and the only even one.<p>The question is: what is the difference between <i>your</i> existence and the existence of pi? Maybe there isn&#x27;t any.