One of the most pernicious myths in the postscientific era is formulated by
Einstein himself:
"Guided by empirical data, the investigator rather develops a system of
thought which, in general, is built up logically from a small number of
fundamental assumptions, the so called axioms. We call such a system of
thought a theory."
The Juggler is hinting at a situation where a lot of information is somehow
extracted from a source containing a small amount of information ("small
number of fundamental assumptions") and guess which god-like creature has
the magic power to do so. In fact, the axioms (premises whose origin is
outside the theory) are much more than "a small number". If the author
presents them explicitly so that anybody can verify the validity of the
derivation, he is honest. If the author hides the additional axioms
sometimes, he is a juggler. If he always hides them, he is a Juggler.
Two examples:
1. Lorentz transforms cannot be deduced from Einstein's original two
postulates. Two additional axioms are needed (see http://www.wbabin.net/valev/valev3.htm }.
2. The frequency shift factor 1+Phi/c^2 is a corollary of the NEGATION of
the postulate of constancy of the speed of light (see again http://www.wbabin.net/valev/valev3.htm ).
It makes a lot of sense to revise the so called axiomatic (deductive)
systems by giving a comprehensive answer to the question: What follows from
what?