"If one applies this to the universe in total, one reaches a remarkable conclusion. ...Namely, if, in the universe, heat always shows the endeavour to change its distribution in such a way that existing temperature differences are thereby smoothened, then the universe must continually get closer and closer to the state, where the forces cannot produce any new motions, and no further differences exist."
January 1, 1970
https://en.wikiquote.org/wiki/Thermodynamics