• In general, given two categories, $C$ and $D$, there is a category $Fun(C,D)$ whose objects are functors between $C$ and $D$, and morphisms are natural transformations between these functors. You can write down your favourite definition af adjunction in this category, and work out what this gives you for an adjunction bewteen two natural transformation – Thibaut Benjamin Mar 3 at 10:52