Reviewed by: Debating Medieval Natural Law: A Survey by Riccardo Saccenti R. S. White Saccenti, Riccardo, Debating Medieval Natural Law: A Survey, Notre Dame, University of Notre Dame Press, 2016; cloth; pp. xiii, 155; R.R.P. US $45.00; ISBN 9780268100407. Natural law is an ancient and abiding way of thinking about the relationship between morality and law. Extremely simple in its premise, that knowledge of the difference between right and wrong is innate and 'written on the heart' as a way of preserving existence, the doctrine has led to vast amounts of commentary on its endless complexities and its very existence or otherwise. As Aquinas put it, 'Good is to be done and pursued, and evil is to be avoided'. However, natural law was also argued for in pre-Christian times, by Plato, Cicero, and others, using not Christian notions of God's divine purposes nor conscience, but reason alone to deduce its existence. Within the later Christian cosmology, conscience was considered central as the innate, God-given faculty, but some Christian thinkers did not draw the conclusion that natural law itself is also innate, insisting instead that God's emissaries on earth are needed to pass down divine law. Meanwhile, after its heyday in medieval and early modern times there have been revivals of natural law and its more civic equivalent, natural rights, which in turn underpinned human rights. Throughout history political applications have been based on the justification offered by natural law for resistance to unjust positive (man-made) laws and for issues like conscientious objection, since the argument runs that positive law must be consistent with natural law or it is no law at all, and can—indeed in some cases must—be broken. However, it needs to be said that Riccardo Saccenti's book is probably not the best place for beginners. Despite its inviting subtitle (A Survey) and its brevity (eighty pages of text, and almost the same of notes), the account presupposes some acquaintance with the mountain of scholarship on the subject. In particular, its intended audience is most likely those in the Natural Law Forum at Notre Dame, which has its own important journal. The subtitle could really be limited to 'A survey of twentieth-century literature' on medieval natural law theories, rather than implying a history of natural law. Furthermore, given the medieval lens, generally speaking the primary concentration is on theological approaches rather than historical, secular, or philosophical ones. Even more specialized, there is a focus on a particular medieval debate on distinctions between lex naturalis (natural law) and ius naturale (natural rights). Within its chosen parameters, Debating Medieval Natural Law is a challenging and important analysis. [End Page 243] R. S. White The University of Western Australia Copyright © 2019 Parergon