  Starting from the swampland distance conjecture, and using the species bound
for a large number of weakly-coupled particles, we give a derivation of the
recently proposed trans-Planckian censorship conjecture. Our argument
demonstrates how a quantum gravity principle requires that trans-Planckian
quantum fluctuations should never cross the Hubble horizon. We also comment on
how logarithmic corrections to the de-Sitter conjecture arise naturally from
such an approach when one relaxes the requirement of traversing parametrically
large distances on field space.
