 Carnap (1963, §24.D) used the Ramsey sentence for distinguishing between the analytic and synthetic components of higher-order theories (Uebel 2016, §3.5), and Lewis (1970) significantly modified the Ramsey sentence to arrive at explicit definitions of secondary terms (Andreas 2017, §4.4). This Ramsey-Lewis sentence has become central in the philosophy of mind (Levin 2017, §4.1) and philosophical methodology (Papineau 2016, §2.3).