  Setting aside anthropic arguments, there is no reason why the universe should
initially favour a net expanding phase rather than one experiencing a net
contraction. However, a collapsing universe containing "normal" matter will end
at a singularity in a finite time. We point out that there is a mechanism,
derived from non-perturbative effects in Quantum Field Theory in a finite
volume, which may provide a bias towards expansion when the spacetime volume
shrinks, by dynamically violating the null energy condition, without the need
for modified gravity or exotic matter. We describe a scalar field component
subjected to this non-perturbative effect in a cosmological background and
consider its impact on a contracting phase. We discuss how this could
dynamically generate the necessary initial conditions for inflation to get
started, or form part of the mechanism for a non-singular cosmological bounce.
