 J.L. Mackie (1977) famously criticizes this picture of moral properties in his extended argument against the objectivity of ethics. Mackie claims to find something like it in the work of a number of historical figures, including Kant and Sidgwick, but his clearest presentation of the picture comes in his remarks about Plato. Mackie writes: “In Plato’s theory the Forms, and in particular the Form of the Good, are eternal, extra-mental, realities. They are a very central structural element in the fabric of the world. But it is held also that just knowing them or ‘seeing’ them will not merely tell men what to do but will ensure that they do it, overruling any contrary inclinations. The philosopher-kings in the Republic can, Plato thinks, be trusted with unchecked power because their education will have given them knowledge of the Forms. Being acquainted with the Forms of the Good and Justice and Beauty and the rest they will, by this knowledge alone, without any further motivation, be impelled to pursue and promote these ideals” (Mackie 1977, 23–24).