That quote has the self-referential quality of a Douglas Hofstadter construct and the subtlety of a Zen koan. It reminds me of Socrates explaining his wisdom: he knows that he doesn't know, as oppose to the fools who think they do. Some ancient variations from Sanskrit and Chinese got it wrong, claiming "he who knows, and knows that he knows is wise; follow him". Sounds like dictation from the king.
The human brain craves certainty. We want leaders who know. Socrates questioned authority and was executed for corrupting young minds.
But certainty is the enemy of understanding. The principle of impermanence trumps certainty. Yesterday's certainties turn into tomorrow's jokes. It used to be so obvious that everything revolves around our flat earth and was made by god so we could play like his children, and earth is our kindergarten except when we eat to much fruit from the tree of knowledge.
Those of faith may interpret the quote to suggest that with age, youthful egoism gives way to spiritual wisdom. The arrogant tools of scientific inquiry are seen as limited. What is unlimited is opening to the infinite revelations of transcendent being, a continual surrender to something bigger than the delusions of self-hood, the desire for a permanent, absolute truth.
Those of science may see the irony of the word "believe" and will get the hint; science is not a belief system. However, professional scientists can be guilty of blind faith in their own specialized system, and have little time or patience for anything judged to be nonsense. Skepticism serves science well, but only after there is a believable foundation to build on. Seldom is the foundation re-examined; that would be a waste of time and energy, and could drive a brain mad. Science makes the a priori claim that there is nothing so exciting as a proof that the foundation needs to be re-built, but many real human scientists don't seem to act that way.
When your foundation eventually crumbles, do you experience suffering or bliss? Is it possible to avoid the suffering by remaining detached from all foundations? Will your loved ones care to be with with you if you attain a high level of detachment from them? Will you be able to practice medicine if you doubt the techniques? Will you survive if you don't care? I remain skeptical about excessive detachment; seems like an attachment. The Chinese Book of Changes noted how things have a way of changing into their opposite when they become too extreme.
Some may see the quote as getting back to the fundamental form of pure skepticism. I'm not so sure anymore, about anything whatsoever, except for one subjective certainty: I have a consciousness that comes and goes, and behind that consciousness is a vast complex of subtle connections with everything unconscious, and with everything that has been and now is, including all life and all humanity. These connections drive my consciousness from one state to the next.
With an act of will, my consciousness can be focused. Sometimes, when my will seems free, I freely focus my consciousness on the tragedy of the impermanence of consciousness itself, and this fills me with a sorrowful compassion for all consciousness everywhere, and this compassion exists beyond skepticism.
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"Impermanence" is the name of this blog because this ancient principle is worthy of contemplation. There used to be a different blog title and description here, but now it's gone. This picture used to look exactly like me, but now now. We remember Heraclitus couldn't step into the same stream twice, but we forget his name: Ηράκλειτος. China's "I Ching" 易 經 Book of Changes is an ancient classic, but even before that, Sanskrit already had a word for the principle of impermanence: अनित्य