 On the surface, Mill’s motivations towards idealism is epistemic—that we can never experience unmediated non-mental objects, and so cannot be warranted in believing in their existence. But the argument goes deeper, suggesting that we cannot even imagine what it would be to believe in the existence of non-mental objects. “[E]ven an imaginary object is but a conception, such as we are able to form, of something which would affect our senses” (Examination, IX: 6). Indeed, Mill at times suggests a semantic version of the argument, which would establish that the very meaning of our words—determined, as they are, by experience—obstructs us from referring to anything beyond experience.