Let us say that we have accepted the mathematical existence of lines. I then intersect them at a point and have a new thing I call an angle. In the example the lines are analogous to axioms and angle to an emergent property. The question is what is the existential status of the angle? Its existence depends upon the lines so it could not have existed before the axioms were set. If so how could something simply go from not existing to existing. Can we even talk of the angle not existing before the axioms were defined? Does the existence of the angle exist in the nature of a line and being able to arrange it? What this example also begs is what is meant by existent. Do we mean something that exists objectively or in some other way? I think the place to start is by asking where we got the idea for our lines [or whatever particular axioms we are considering]. To me it seems that the foundations of math must have their origin in experience. That is, the foundation of math is a posteriori, not a priori.