We take this or that just act, ignore all irrelevant features, and make it stand for and represent all other just acts.
The only difficulty in the way of such a system of ethics which Berkeley mentions is the practical difficulty of reaching agreement with regard to its definitions. The definitions which mathematics employs are not questioned, because the learner comes to them with no preconceived ideas. He is willing to take them on trust. But in ethics it is otherwise. Men approach the subject with presuppositions of their own. They cling to these primitive convictions, and refuse to come to any agreement in the definition of terms.
One very real difficulty which Locke had mentioned is denied by Berkeley. Locke had pointed out that the complexity of moral ideas increases the difficulty of dealing with them by the mathematical method. But Berkeley sees nothing in this.[1] Yet if 'complexity' be extended to include the relations and context of moral ideas, Locke's point becomes a very real one. On Berkeley's theory, if we take a particular triangle it is possible to abstract what is irrelevant to its triangularity, and the particular may be taken to stand for all particulars of the same kind. And, as we have seen, Berkeley thinks the same thing may be done in ethics. But it is not thus possible to isolate a just act. If it be cut loose from its context, it may be no longer a just act. Its justice may consist precisely in the complex relations in which it stands to its environment. But though Berkeley was certainly not aware of this difficulty in the days of the Commonplace Book, it is clear from Alciphron that he appreciated it later. This may well have been one of the reasons why he abandoned the project of writing a mathematical science of ethics.
But probably another reason weighed with Berkeley. If ethics be a science demonstrable in the same way as mathematics, why has God allowed so much diversity of opinion with regard to its definitions and propositions? There is universal agreement that 2+2=4. This agreement Berkeley attributes to God: God brings it about, arbitrarily but not capriciously,
- ↑ Commonplace Book, I, p. 51.
