 Another (related) way of differentiating pluralism and relativism, employed by Berlin and others, holds that pluralism accepts a basic ‘core’ of human values, and that these and other values adopted alongside them in a particular context fall within a common ‘human horizon’ (1990, 12). Though Berlin’s usage is not entirely consistent, this horizon is best thought of as a boundary enclosing any form of human conduct that is comprehensible to other human beings in virtue of their shared humanity, whether or not the conduct is deemed acceptable. (Actions may be comprehensible but unacceptable for more than one reason, including mistaken empirical beliefs and – jointly or separately – what is known in religious terminology as original sin, the innate human propensity to behave immorally.) Beyond the horizon lies behaviour we cannot make sense of, and therefore regard as insane or irrational, such as the worship of wood simply because it is wood, or sticking pins into the flesh of living people just because it is pleasurable to pierce resilient surfaces, without regard to or even enjoyment of the pain this causes. The ‘core’ of shared or universal values accounts for our agreement on at least some moral issues, for example, the immorality of ‘slavery or ritual murder or Nazi gas chambers’ (1990, 19). This view rests on a belief in a basic, minimum, universal human nature beneath the widely diverse forms that human life and belief have taken across time and place. It may also involve a belief in the existence of a specifically ‘moral sense’ inherent in human beings. Berlin seems to have believed in such a faculty (which he refers to under this name), and linked it to empathy, but did not develop this view in his writings.