[DoodleDawg]

This is true — but if you appeal to a congressional act to claim that his mother could transmit citizenship to him, you are implicitly relying on a [normal] congressional act; but such an act cannot alter the Constitution, and as congress is only given the power to define a uniform rule of naturalization to rely upon this is to implicitly assert that he is a naturalized citizen which is contrary to the claim that he is natural born. (i.e. it is self contradictory.)

If Congress is to adopt a uniform set of rules for naturalization then don't they have to first define who doesn't need to be naturalized, i.e. natural born citizens?

[OneWingedShark]

f Congress is to adopt a uniform set of rules for naturalization then don't they have to first define who doesn't need to be naturalized, i.e. natural born citizens?

No. They only have power over declaring the rule of naturalized citizens.

Your assumption is akin to saying don't we need to define what negative integers is before we define positive integers?, and the answer is no.
We can define positive integers by induction as:

1. Any integer whose value is greater than z is positive. [Dfn]
2. Any positive integer incremented by one is itself a positive integer. i.e. P(n) -> n+1
3. One is a positive integer. (Zero is an integer, 0+1 yields 1, which is a value greater than zero.)

We now have a definition of positive completely independent of the notion of negative numbers; we could do similar to define negative numbers... though the magnitude actually would tie into positive numbers.