D.S.Heersink makes a common error commited by modern sophists; and that is of presuppossing the truth of a premise on the basis of the erroneous human authority of previous modern sophists. In this case the previous modern sophists are the empiricists David Hume and G.E.Moore. This appeal to fallible human authority is not philosophy but ideology because philosophy proves its conclusions as opposed to presuming their truth based on fallible human authority. D.S presumes that Hume and Moore already decisively refuted the natural law theory(NLT). However, they have done nothing of the sort. Anyone educated in moral philosophy(ethics) as exposited by Aristotle and Thomas Aquinas knows the principles of ethics present in theoretical philosophy, specifically the scientific theory of human nature and the Aristotelian science of metaphysics as exposited by Aquinas and Aristotle. Aquinas derives moral goodness from human nature in the natural moral law; see his Summa Contra Gentiles Book III:129. This is a little known text that proves the existence of the natural moral law, not from the eternal law of God as in the Summa Theologiae but from human nature itself. In my course paper as a graduate student in philosophy I wrote on this subject and how it relates to the so-called "naturalistic fallacy" arguments against the NLT. I discovered that G.E.Moore and his empiricists/illogical positivists allies are instead the ones who commit a fallacy. They commit the fallacy of equivocation between between a real distinction and a logical(conceptual) distinction. Their fact/value distinction is a reflection of the logical(conceptual) distinction between being and goodness in general; however there is no real distinction between being and goodness in general. In reality being and goodness in general are the same and this is what allows Aquinas to derive moral goodness in the natural moral law from goodness in general as applied to the good and being of human nature. By means of the real identity but logical distinction beween the goodness and being of human nature, Aquinas is able to derive moral goodness from the perfections of human nature without violationg the logical distinction between the being of human nature and goodness in general( reflected in the fact/value distinction). Therefore in the G.E.Moore/David Hume objections to the NLT they commit a fallacy of equivocation between the real distinction between fact and value, which is false and is opposed by Thomistic NLT, and a logical(conceptual) distinction between fact and value, which is true and is affirmed by Thomistic NLT. Thus NLT do not confuse facts and "values" and there is no such thing as a naturalistic fallacy. Instead, it is Moore and Hume and their like that commit the fallacy of equivocation between a real distinction and a logical distinction. Further, contrary to Heersink's comments this book by Rommen is an excellent study in the history of NLT detailing the ancient sophists, like their modern sophistic counterparts, who rejected the natural moral law to the corruption of NLT by classical liberalism as represented by John Locke and other philosophical revolutionaries of the 18th century(they used natural law as a prop for revolution,sedition and classical liberalism). Further D.S.Heersink is seriously ignorant when he comments that only the Catholic Church's moral theology embraces Thomistic natural law. First, Thomistic NLT as proven in Summa Contra Gentiles III:129 and as articulated in his Commentary on Aristotle's Nicomachean Ethics and Politics and certain strictly philosophical segments of the Summa Theologiae's Treatise on Law and Treatise on Justice and Treatise on Temperance; are essentially distinct from theology because their arguments are based on reason alone. Cicero and Aristotle held to an elementary version of NLT and neither where theologians and both were pre-Christians. Aquinas frequently refers to both Cicero and Aristotle in his writings pertaining to NLT without using them as final authorities in his argumentation for the conclusions of NLT; unlike modern sophists who appeal to fallible human authority as their final word. Aquinas actually proves all the conclusions of NLT using reason alone; which Heerskink would know if he was not ignorant of the works of Aquinas. For example in the Summa Contra Gentiles Book III:122 Aquinas proves that every intentional frustration of the procreative good of human sexuality is intrinsically evil and he does the same in his disputed questions on moral evil question 15, article 3. Since every contraceptive act and every homosexual act is an intentional frustration of the procreative good of human sexuality, by aaa-I syllogism Aquinas proves by reason alone that every contraceptive act and every homosexual act is intrinsically evil. Therefore he lists contraception and homosexual behavior as species of the unnatural vice which violates the cardinal virtue of temperance. As far as abortion is concerned, while it is true that Aristotle erred on this particular issue it was not because of his NLT principles but despite them. Aquinas since he condemned contraception, necessarily condemned all abortion as intrinsically evil since every abortion is the intentional killing of the result of human procreation irrespective of when human life begins. These conclusions of NLT are rooted in Aristotle's proven conclusions of ethics, especially his theory of the virtue of temperance and that of natural justice(which Aristole in his Ethics affirms is universal and transcends every civil law and every political society). Notice in these arguments there is no reference to religious faith and Cicero, Aristotle, and also Aquinas(SCG III:129 and his strictly philosophical texts) exemplify the capacity of moral philosophers to affirm and articulate NLT without reference to religious faith. Further, the best defense of NLT is not Robert George. He is a token political conservative professor at Princeton University who affirms the "New Natural Law Theory" invented by Germain Grisez and promoted by John Finnis and Martin Rhonheimer. This theory, with absurd, ahistorical, and disastrous results, is the result of an attempt to save NLT from the empiricists criticism by Hume and Moore, by conceding their objections to classical NLT and then constructing a NLT that is the product of Kantian ethics and its divorce of practical reason from theoretical reason with Thomistic NLT. This explicitly contradicts Aquinas' own proof of the natural moral law from the theoretical knowledge of human nature as presented in SCG III:129 and has disastrous results regarding the nature of human happiness as consisting in intellectual virtue. Further, the nonsense is the empiricism of David Hume in his Treatise Against Human Nature and the illogical positivism of G.E.Moore in his Principia Ethica both of which theories of knowledge are self-contradictory and therefore logically impossible. In fact any objection to NLT on the grounds that it presupposes the reality of human nature, while accurately representing NLT, is a false objection that presupposes the empiricists denial of nature, human nature, and especially the human intellect's knowledge of nature and human nature. Similarily all denials of nature, human nature, or human intellectual knowledge of these two are based on errors contrary to philosophical physics or to scientific epistemology(includes theory of knowledge). Like the ancient sophists who opposed NLT, these modern sophists start with their erroneous theories of knowledge and fit everthing including their ethical theories into their erroneous theory of knowledge. Both are systematically and intentionally ignorant of the scientific exposition of philosophy provided by Aristotle and Thomas Aquinas. As a result of their ignorance they commit massive errors in their works including a fallacy of equivocation between a real distinction and a logical(conceptual) distinction in their very assertion that NLT commits their invented "naturalistic fallacy". Finally, the best words to end on are the words of Cicero, as quoted from Rommen's book. These words indicate how far classical NLT is from modern political sophistry, masquerading as philosophy, and from the modern political ideologies of classical and modern liberalism; all of which affirm some form of legal dictatorship known as legal positivism and which denies the very existence of a natural moral law. Cicero states that "true law is right reason in agreement with nature; it is of universal application, unchanging and everlasting; it summons to duty by its commands, and averts from wrongdoing by its prohibitions... We cannot be freed from its obligations by senate or people... one eternal and unchangeable law will be valid for all nations and all times... Whoever is disobedient is fleeing from himself and denying his human nature,and by reason of this very fact he will suffer the worst penalties, even if he escapes what is commonly considered punishment." pg. 21 footnote 12 of Heinrich A. Rommen. The Natural Law: A Study in Legal and Social History and Philosophy. Wow!This was not stated by a "religious fundamentalist", a category invented by modernity, but by the non-Christian philosopher Cicero. Now what is true of individuals also pertains to the political society made up of individuals that violate the natural moral law and this is the modern state; the modern state is in violation of the natural moral law because of its promotion of contraception,abortion, sodomy, and pornograpy( the crimes of the modern state) and it will suffer the worst penalties, even if it escpaes what is commonly considered punishment. Unfortunately, my nation the United States of America with its U.S. constitution has been in violation of the natural moral law from its very beginning because of its classical liberalism and racist slavery and now because of the previously mentioned moral evils affirmed by modern liberalism. As far as what texts I recommend to anyone who wants to study ethics and political science. Start with Aristotle's Nichomachean Ethics and the Thomistic commentary on this strictly philosophical work. Next study the treatise that Aquinas has on happiness and the treatises on the cardinal virtues, and the treatise on law as presented in his Summa Theologiae. Finally study his commentary on Aristotle's Politics. Many of Aquinas' political writings are collected in an edition by Cambridge. Francis Vitoria is the best Thomistic commentator on matters of political science. Unfortunately, there is no single work that unites all these Thomistic texts into a complete scientific exposition of ethics nor into a complete sicientific exposition of political science. This is something that hopefully will be produced by me in the future. John F. Wippel's "The Metaphysical Thought of Thomas Aquinas" is an excellent historical work that starts this process in metaphysics.