Being, difference, and falsehood › What the argument leaves open

A reasonable objection is that redefining non-being has not refuted every possible Eleatic concern. If Parmenides' prohibition concerns absolute nothingness, showing that motion differs from rest need not make absolute nothingness thinkable. The visitor's success can instead be assessed against the problem he needs to solve: articulating difference, negative predication, and false discourse without collapsing them into sheer nothing.

Another objection concerns the move from metaphysics to language. An account of how kinds combine does not by itself provide evidence about whether a particular claim is true. The argument about Theaetetus relies on what he is actually doing. A metaphysical possibility of false assertion cannot replace observation or testimony when judging an assertion. In the consultant example, someone still needs the review record.

A third limit concerns fiction and empty names. Because the dialogue's decisive example uses an existing subject, its explanation should not be advertised as a complete solution to every statement about a fictional city or an impossible object. Such questions can be compared with the Sophist, but the comparison introduces further problems. We should not silently treat them as resolved by the sitting and flying example.

These limits make the contemporary applications more useful. In a hypothetical software report, an invented result can be meaningful enough to deceive even if its asserted success never occurred. In a disagreement with a friend, denying one accusation does not establish every positive description of one's conduct. In both cases, we can identify the subject, specify what was asserted, and ask which evidence bears on that assertion. These are applications of the distinctions, not predictions Plato made about our institutions or technology.

The dialogue also gives readers a way to assess apparent expertise. The ability to answer every question fluently can be separated from knowledge of the subject. That distinction does not prove that a confident speaker is a sophist. It directs attention to whether the person can explain the relationships they assert and respond to relevant corrections. Our own classifications deserve the same scrutiny.

The Sophist connects the work of defining with the work of asserting. We distinguish kinds to understand what something is; we investigate their relations to understand what can be said about it. A false sentence can use the same familiar words as a true one. The difference lies in what it asserts about its subject, and that is where an inquiry into its truth must continue.