 There are parallels here with discussion in ethics, where some commentators have supposed, likewise, that a full appreciation of certain cardinal moral concepts depends upon being able to grasp, through first hand experience, the relevant phenomenology. Raimond Gaita, for example, argues that our concept of the individuality of other persons (in the sense that is relevant when we speak of them as being from a moral point of view irreplaceable) is not fully expressible independently of reference to the phenomenology of our moral experience. The sense of this concept is given in, for instance, the experience of being haunted by the victim of your wrong-doing, where it this particular individual who haunts you, rather than some representative of humanity in general, or someone whose individuality can be adequately specified simply by reference to, for example, their distinguishing empirical properties (of hair colour, height, or whatever it may be) (1991, p. 51).