phrase meaning - This only begs the question

I am reading a book SICP
it stats:

As a case in point, consider the problem of computing square roots. We can define the square-root function as

It will not help matters to rephrase this definition in pseudo-Lisp:

: (define (sqrt x)
:   (the y (and (>= y 0)
:               (= (square y) x))))

This only begs the question.

What does beg the question mean?

Answer

I do not know Lisp, still less mathematics, but 'begging the question' means, in an argument, to assume the conclusion in one of the premises. Many people use the phrase “begging the question” incorrectly when they use it to mean, “prompts one to ask the question”. That is NOT the correct usage. Begging the question is a form of circular reasoning.