Tooley's solution to the inference problem

Conclusion

Tooley's speculative theory, I have tried to show, is beset with difficulties. I warned that this theory threatens to fail in its goal of illuminating the possible nature of a necessitation relation if it employs radical principles about parts and wholes and universals. Secondly, I argued that regardless of how we interpret the crucial phrase ‘existing only as a part of’, the speculative theory cannot solve the inference problem without appealing to such radical principles. Finally, I considered and rejected a version of Tooley's speculative theory that attempts to solve the inference problem using the Indiscernibility of Identicals.

I conclude that the speculative theory fails. Tooley must fall back to the stipulative theory and live with the lack of an illuminating solution to the inference problem. But this is not to admit defeat. While it would be nice to have a more complete account of its workings, we may view the introduction of the necessitation relation as a theoretical posit, analogous to the positing of subatomic particles in physics to account for various data.