  In these lectures I review the status of gravity from the point of view of
the gauge principle and renormalization, the main tools in the toolbox of
theoretical particle physics. In the first lecture I start from the old
question "in what sense is gravity a gauge theory?" I will reformulate the
theory of gravity in a general kinematical setting which highlights the
presence of two Goldstone boson-like fields, and the occurrence of a
gravitational Higgs phenomenon. The fact that in General Relativity the
connection is a derived quantity appears to be a low energy consequence of this
Higgs phenomenon. From here it is simple to see how to embed the group of local
frame transformations and a Yang Mills group into a larger unifying group, and
how the distinction between these groups, and the corresponding interactions,
derives from the VEV of an order parameter. I will describe in some detail the
fermionic sector of a realistic "GraviGUT" with SO(3,1)xSO(10) \subset
SO(3,11). In the second lecture I will discuss the possibility that the
renormalization group flow of gravity has a fixed point with a finite number of
attractive directions. This would make the theory well behaved in the
ultraviolet, and predictive, in spite of being perturbatively
nonrenormalizable. There is by now a significant amount of evidence that this
may be the case. There are thus reasons to believe that quantum field theory
may eventually prove sufficient to explain the mysteries of gravity.
