主题：来个好玩的吧 -- 长颈鹿

凯恩斯主义的宏观经济学在80年代已经破产。原因是出现了比他更了不起的经济理论。凯恩斯以前在剑桥曾经帮助过一个叫Frank P. Ramsey（外链出处）的人。也就是这个Ramsey在20来岁时写的三篇论文，彻底结束了凯恩斯的时代。

Work

In 1927 Ramsey published the influential article Facts and Propositions, in which he proposed what is sometimes described as a redundancy theory of truth.

One of the theorems proved by Ramsey in his 1930 paper On a problem of formal logic now bears his name (Ramsey's theorem). While this theorem is the work Ramsey is probably best remembered for, he only proved it in passing, as a minor lemma along the way to his true goal in the paper, solving a special case of the decision problem for first-order logic. As it happened, the lemma was not actually necessary for the results he obtained from it. However, Alonzo Church would go on to show that the general case of the problem Ramsey was tackling is unsolvable (see Church's theorem), while, ironically, a great amount of later work in mathematics was fruitfully developed out of the ostensibly minor lemma, which turned out to be an important early result in combinatorics, supporting the idea that within some sufficiently large systems, however disordered, there must be some order. So fruitful, in fact, was Ramsey's theorem that today there is an entire branch of mathematics, known as Ramsey theory, which is dedicated to studying similar results.

His philosophical works included Universals (1925), Facts and propositions (1927), Universals of law and of fact (1928), Knowledge (1929), Theories (1929), and General propositions and causality (1929). Wittgenstein mentions him in the introduction to his Philosophical Investigations as an influence (but not as great an influence as Piero Sraffa).

“想像有队外星人军队在地球降落，要求取得R(5,5)的值，否则便会毁灭地球。在这个情况，我们应该集中所有电脑和数学家尝试去找这个数值。若它们要求的是R(6,6)的值，我们要尝试毁灭这班外星人了。”