… is from pages 134-135 of the 2000 Liberty Fund edition of Frederic William Maitland’s profound 1875 dissertation at Trinity College, Cambridge, A Historical Sketch of Liberty and Equality:
Adam Smith has remarked that the laws made about religion and commerce have been peculiarly bad, and we may notice that laws on these two subjects were the first laws condemned as essentially going beyond the proper province of law…. There are no subjects with which the statesman has to deal, the logic of which is so elaborate and so difficult. This last reason, though it is not often expressly insisted on (we do not like to confess our own ignorance, or impress on others their ignorance when we have nothing to substitute for it) is really all-important. The statesman has to consider the good he may do by interfering on the right side, the evil he may do by interfering on the wrong side, and also the probability of his knowing which the right side is. The most convincing pleas for laisser faire, and the most convincing pleas for religious toleration, are those which insist à priori on the great “probable error” of any opinions on matters of religion, and matters of political economy, and those which relate à posteriori the history of the well-intentioned failures of wise and good men.