  In classical phenomenological thermodynamics the first and second laws can be
regarded as independent statements. Statistical mechanics provides a
microscopic substratum that explains thermodynamics in probabilistic terms via
a microstate probability distribution ${p_i}$. We study here a hitherto
unexplored microscopic connection between the two laws. Given an information
measure (or entropic form), each of the two laws implies the other through the
process $p_i \to p_i+dp_i$.
