  In this paper we consider Quadratic Gravity as a low energy effective field
theory of some unknown UV-complete theory of gravity. Using the spin-2 ghost
pathology that occurs in Quadratic Gravity, we derive maximum value for the
classical cut-off of the low energy effective field theory in various
configurations. We then add on higher order, bottom-up, effective terms. At
each order we allow the introduction of non-minimally coupled scalar field
terms, and we calculate the vacuum expectation value of the theory under an
assumed $\mathbb{Z}_2$ symmetry breaking of the scalar field. This symmetry
breaking leads us to introduce a constant in the action which is required to
ensure that the physical spin-2 degree of freedom is massless in the flat space
approximation, an implicit assumption we make throughout the work. We then
consider the case in which we do not fine tune the introduced constant, which
leads to an (Anti-)de Sitter solution about which we can then expand. The sign
of the chosen cosmological constant is the major factor in determining whether
the geometry is de Sitter or Anti-de Sitter. Then expanding about this geometry
allows us to increase the theoretical classical cut-off as compared to the flat
space case by an amount that is proportional to the free cosmological constant
parameter.
