There can be no "fundamental definition of the theory" unless Einstein's 1905 false light postulate and its absurd consequences are officially abandoned:
http://www.amazon.com/Trouble-Physics-String-Theory-Science/dp/0618551050 Lee Smolin, The Trouble With Physics, p. 226: "Einstein's special theory of relativity is based on two postulates: One is the relativity of motion, and the second is the constancy and universality of the speed of light. Could the first postulate be true and the other false? If that was not possible, Einstein would not have had to make two postulates. But I don't think many people realized until recently that you could have a consistent theory in which you changed only the second postulate."
http://www.amazon.com/Faster-Than-Speed-Light-Speculation/dp/0738205257 Joao Magueijo, Faster Than the Speed of Light, p. 250: "Lee [Smolin] and I discussed these paradoxes at great length for many months, starting in January 2001. We would meet in cafés in South Kensington or Holland Park to mull over the problem. THE ROOT OF ALL THE EVIL WAS CLEARLY SPECIAL RELATIVITY. All these paradoxes resulted from well known effects such as length contraction, time dilation, or E=mc^2, all basic predictions of special relativity. And all denied the possibility of establishing a well-defined border, common to all observers, capable of containing new quantum gravitational effects. Quantum gravity seemed to lack a dam - its effects wanted to spill out all over the place; and the underlying reason was none other than special relativity."
http://www.pbs.org/wgbh/nova/physics/blog/author/fwilczek/ Frank Wilczek: "Einstein's special theory of relativity calls for radical renovation of common-sense ideas about time. Different observers, moving at constant velocity relative to one another, require different notions of time, since their clocks run differently. Yet each such observer can use his "time" to describe what he sees, and every description will give valid results, using the same laws of physics. In short: According to special relativity, there are many quite different but equally valid ways of assigning times to events. Einstein himself understood the importance of breaking free from the idea that there is an objective, universal "now." Yet, paradoxically, today's standard formulation of quantum mechanics makes heavy use of that discredited "now." Playing with paradoxes is part of a theoretical physicist's vocation, as well as high-class recreation. Let's play with this one. (...) As we've seen, if a and b are space-like separated, then either can come before the other, according to different moving observers. So it is natural to ask: If a third event, c, is space-like separated with respect to both a and b, can all possible time-orderings, or "chronologies," of a, b, c be achieved? The answer, perhaps surprisingly, is No. We can see why in Figures 5 and 6. Right-moving observers, who use up-sloping lines of constant time, similar to the lines of constant t2 in Figure 2, will see b come before both a and c (Figure 5). But c may come either after or before a, depending on how steep the slope is. Similarly, according to left-moving observers (Figure 6), a will always come before b and c, but the order of b and c varies. The bottom line: c never comes first, but other than that all time-orderings are possible. These exercises in special relativity are entertaining in themselves, but there are also serious issues in play. They arise when we combine special relativity with quantum mechanics."