The main goal of Kenneth R. Westphal?s How Hume and Kant Reconstruct Natural
Law: Justifying Strict Objectivity without Debating Moral Realism is to
defend the objectivity of moral standards and natural law and thus avoid the
discussion about moral realism and its alternatives by interpreting Hume and
Kant in a constructivistic sense. The reason behind the author?s disagreement
with both: moral realism and non-realism (its alternative) is our inability
to properly understand and answer one of the two parts in Socrates? question
to Euthyphro: ?Is the pious loved by the gods because it is pious, or is it
pious because it is loved?? Moral realists cannot provide an answer to its
second part, since it is not possible to prove that moral standards are not
artificial; conversely, moral non-realists cannot provide an answer to its
first part, since it is not possible to avoid the relatitvity of moral
standards. The author tends to solve this problem by avoiding the
confrontation between moral realism and non-realism and thus choosing the
constuctivistic stance that, as he argues, can be found in both Hume?s and
Kant?s theories. The main point of this stance is that moral standards are
indeed artificial, yet not arbitrary. He proves this by pointing out that
both Hume and Kant treat the moral standards as a social fact (that is,
artificial), but also as objective. Westphal points out that Hume explicitly
writes about moral standards as a social fact, while showing that, at the
same time, his theory of justice, which precedes all of the moral standards,
is established independently of his theory of moral sentiments (potentially
leading to moral relativism). In this manner, he provides the objectivity of
those standards. On the other hand, Kant?s theory is interpreted as advanced,
yet similar to Hume?s in its structure. The crucial similarity is that both
Hume and Kant interpret the moral standards as a social fact (that is, as an
artificial) and, at the same time, as the objective ones. Kant, unlike Hume,
provides this objectivity by using a specific moral criterion - a categorical
imperative. Those assumptions will be used as the main premises of a
distinctively inspiring interpretation of Hume?s and Kant?s theories of
justice.
The contstructivistic defence of the objectivity of moral standards and natural law that does not require the debate on moral realism