A followup to Marc’s post on motive in law. Marc notes that motive remains salient in constitutional law, but not in tort or criminal law. I’d like to add just a couple of points.
First, when it comes to constitutional law, motive is especially important in contemporary Religion Clause jurisprudence. The Lemon test (much-derided, but still extant, in my opinion, even after last term’s Bladensburg Cross case) makes government motive central to Establishment Clause cases. In the Free Exercise context, government motive figures prominently as well. The Masterpiece Cakeshop decision turned almost entirely on the Court’s inferences about the anti-religious motives of Colorado state officials.
Marc wonders why motive should be relevant in constitutional law, when it has lost its relevance in tort law. It’s a good question. Because motive is even more elusive in public law than in private law. Take contract law, for example. Classical contract law disregards a party’s motives for making a contract. It doesn’t matter why someone makes a contract. The only thing that matters is that the person intends to make a contract–or, rather, that an objective observer would understand that the person intends to make a contract. This is so because a party may have several motivations for making a contract: profit, affection, indifference, etc. To try to figure which motive was the most important is a hopeless task.
The problem is even more compounded when it comes to government motive. In contract law, we’re talking about the intentions of two actors. But government actions turn on the decisions of potentially hundreds of actors, all of whom may have multiple motives. The problem of ascertaining motive is even more difficult in this context.
I’m not sure where all this leads. But Marc is right in pointing out the continued relevance of motive in constitutional law, and its continued irrelevance in private law. It’s a puzzle that demands an answer.
This forthcoming book from Encounter looks fun: 

American liberals and conservatives alike take for granted a progressive view of the Constitution that took root in the early twentieth century. Richard A. Epstein laments this complacency which, he believes, explains America’s current economic malaise and political gridlock. Steering clear of well-worn debates between defenders of originalism and proponents of a living Constitution, Epstein employs close textual reading, historical analysis, and political and economic theory to urge a return to the classical liberal theory of governance that animated the framers’ original text, and to the limited government this theory supports.
as it played out in Mobile, Alabama. There, a community conflict pitted a group of conservative evangelicals, a sympathetic federal judge, and a handful of conservative intellectuals against a religious agnostic opposed to prayer in schools, and a school system accused of promoting a religion called ‘secular humanism’. The twists in the Mobile conflict speak to the changes and continuities that marked the relationship of 1980s’ religious conservatism to democracy, the courts, and the Constitution. By alternately focusing its gaze on the local conflict and related events in Washington, DC, this book weaves a captivating narrative. Historians, political scientists, and constitutional lawyers will find, in Rubin’s study, a challenging new perspective on the history of the Christian Right in the United States.
the religious character of a state? And what kind of constitutional solutions might reconcile democracy with the type of religious demands raised in contemporary democratising or democratic states? Tensions over religion-state relations are gaining increasing salience in constitution writing and rewriting around the world. This book explores the challenge of crafting a democratic constitution under conditions of deep disagreement over a state’s religious or secular identity. It draws on a broad range of relevant case studies of past and current constitutional debates in Europe, Asia, Africa and the Middle East, and offers valuable lessons for societies soon to embark on constitution drafting or amendment processes where religion is an issue of contention.