 This argument from logic to natural language meaning is reminiscent of slippery slope reasoning: it might be challenged at any of the sliding points. For instance, one might argue that there is no real reason (= no reason other than to try to establish the overall conclusion about natural language meaning) to prefer natural deduction formulations of logic over Frege-Hilbert axiomatic ones. Or one might point to an alleged “vast gulf” between logical systems (and the reasoning employed in them) and natural language (and the variety of uses to which natural language lends itself). Still, the project has seemed not just possible but a straightforwardly correct path to investigate.