If both ideas and objective reality conform to the same categories of experience, then the connection between ideas and objective reality is clearly established.

One objection to the argument from error is that another type of objective reality, some other sort of being external to one’s finite mind, might explain the possibility of error just as well. Royce took up this objection in the first volume of The World and the Individual, which was subtitled “The Four Historical Conceptions of Being.” In this extended argument Royce critiqued what he regarded as the main competing conceptions of objective reality so as to strengthen his case for idealism. The