I think the point is that it comes from "within Man" for the senses can , in no way, elicit geometry, algebra and arithmetic. Over a the other place I wrote a piece about the realm of the "will" or man's unconscious which is the source of mathematics, aphoristically.
Back to Masques point about being "part of nature", this is true broadly, but the question is do the above disciplines (geometry, algebra and arithmetic) fit with the external world or the realm of the senses.
The question of a "proper fit" of mathematics leads to "kinematics", trying to shorten this. One can "within one's head" do kinematics such as vectors, determinants, or similar abstracted meanderings.
The moment one does mechanics it is incumbent upon the actor to measure or weigh the effect for then the idea of "weight, or measure or ponderability" is not garnered from within but must be measured. Mechanics is an external driven reality and is not the same as kinematics nor can one "think" about weight in the same manner as the kinematic. Proof must come through measurement .
This doesn't mean that in the science of external reality mathematics should be dismissed but to realize that the movement of science will continue hand in hand with the mathematical should be realized. One example of the mathematical moving along is Lobachevsky's geometry which denies 180 degree triangles and leads to the idea that space is curved, yada, yada, as do some scientists.
Too many assumptions, too many theories, all of which are dependent upon or rigidified upon, by an abstract mathematics thus making it seem like "we can't be wrong" for the mathematics is right but it is not right. lol pragmatic science.
Where does mathematics come from ??; of course from within and comprehending the nature of the abstracted mathematical will help to understand it and its effect in the sciences and its place in nature.