A June 22, 1955 letter from Aldous Huxley to his brother (from p. 28-9 of This Timeless Moment):
Many happy and happier returns! Yes, it is hard to feel old – to be quite serieux, as the ageing bourgeois ought to be! We both, I think, belong to that fortunate minority of human beings who retain the mental openness and elasticity of youth, while being able to enjoy the fruits of an already long experience.
Why there should be so few of these sub-species of homo sapiens, or why the majority of men and women, and even adolescents, should develop mental arterio-sclerosis forth of fifty years before they develop physical arterio-sclerosis is a great mystery.
And yet the fact is obvious. Most people encapsulate themselves, shut up like oysters, sometimes before they have stopped being undergraduates, and go through life barricaded against every idea, every fresh and unconceptualized perception.
It is obvious that education will never give satisfactory results until we learn how to teach children and adults to retain their openness. But the practical problem is as yet hardly considered by professional educators. I was pleased to learn, however, that the General Semantics people here – Hayakawa and the group that puts out that excellent little review "Etc" – have developed methods for training people to pass at will from conceptualized perception to direct virgin perception.
The exercise keeps the mind fresh and sensitive and teaches a wholesome understanding of the function of language and its dangers, when taken too seriously, in the way that all pedants, doctrinaires and dogmatists invariably do, with such catastrophic results.
Speculation: was General Semantics the rationality training of the 20th Century?