 While possibilism itself remains a viable view in the literature, Harold Zellner demonstrated that Prawitz’s and Westphal’s responses did not solve the specific problem Castañeda identified for utilitarianism. This is because, while performing \(\langle A \at t_1 \lamp B \at t_2\rangle\) may be uniquely optimific, it does not follow that performing either of these individual acts at their respective times would be uniquely optimific. For instance, performing \(\langle A \at t_1\rangle\) may not be uniquely optimific if the agent would not perform \(\langle B \at t_2\rangle\)if she first performs \(\langle A \at t_1\rangle\). Zellner (1972: 125) illustrates this with the following case. 