 Another approach is to try to show how simplicity principles follow from other better established or better understood principles of  rationality.[11]  For example, some philosophers just stipulate that they will take ‘simplicity’ as shorthand for whatever package of theoretical virtues is (or ought to be) characteristic of rational inquiry. A more substantive alternative is to link simplicity to some particular theoretical goal, for example unification (see Friedman 1983). While this approach might work for elegance, it is less clear how it can be maintained for ontological parsimony. Conversely, a line of argument which seems better suited to defending parsimony than to defending elegance is to appeal to a principle of epistemological conservatism. Parsimony in a theory can be viewed as minimizing the number of ‘new’ kinds of entities and mechanisms which are postulated. This preference for old mechanisms may in turn be justified by a more general epistemological caution, or conservatism, which is characteristic of rational inquiry.