 While on Albert and Loewer’s account the causal asymmetry is ultimately grounded in the probability postulate, they attempt to derive this asymmetry via a somewhat circuitous route. The first step is to argue that the Mentaculus implies a branching tree structure toward the future on the macrolevel, according to which the universe’s macrostate at a time is compatible with many more different macro-evolutions toward the future than macro-evolutions toward the past. In a second step they argue that this branching tree structure underwrites an asymmetry of counterfactual dependence on the macro-level and thereby supports a broadly Lewisian counterfactual analysis of the temporal arrow of causation. The claim that the Mentaculus implies a temporally asymmetric branching tree structure of the kind postulated by Loewer is criticized in Frisch (2010): since future higher entropy macro states occupy vastly larger regions of phase space than lower entropy past states, thermodynamically normal evolutions, if anything, suggest an upside-down tree  structure.