 All moral principles and norms, Aquinas thinks, can be inferred – as either implicit in, or “referable to” as conclusions from – the moral first principle of love of neighbor as self: ST I-II q. 99 a. 1 ad 2 with q. 91 a. 4c and q. 100 a. 2 ad 2; q. 100 aa. 3 and 11c. But he never displays an example or schema of these deduction-like inferences. Consequently, as noted in 2.7 above, his would-be successors have sometimes proposed that moral principles and norms have the self-evidence of first principles, and sometimes, equally desperately, have offered premises which, though suggested by some of Aquinas’s argumentation or remarks, are incoherent with his general theory – e.g. that natural functions are not to be frustrated.