The Past Hypothesis and the Nature of Physical Laws

Abstract

If the Past Hypothesis underlies the arrows of time, what is the status of the Past Hypothesis? In this paper, I examine the role of the Past Hypothesis in the Boltzmannian account and defend the view that the Past Hypothesis is a candidate fundamental law of nature. Such a view is known to be compatible with Humeanism about laws, but as I argue it is also supported by a minimal non-Humean governing view. Some worries arise from the non-dynamical and time-dependent character of the Past Hypothesis as a boundary condition, the intrinsic vagueness in its specification, and the nature of the initial probability distribution. I show that these worries do not have much force, and in any case they become less relevant in a new quantum framework for analyzing time's arrows--the Wentaculus. Hence, both Humeans and minimalist non-Humeans should embrace the view that the Past Hypothesis is a candidate fundamental law of nature and welcome its ramifications for other parts of philosophy of science.