除了科學家和哲學家，一般人對於任何不確定的東西，
是相當害怕的，因為他們喜歡迅速判斷及立即採取果斷的行動，
而他們的自信心亦是建立在果斷的行動和往往有點盲目的信念之上。
所以「浮沙恐懼症」是大部份行動家的夢魘！
但愛智的人的自信，不是建立在完全避免錯誤之上，
而是建立在有某種程度的把握之上，
而是建立在懂得衡量得失之上，
而是建立在明白自己會勇於修正錯誤之上。
愛智的人相信：勇於修正錯誤，就是迫近真理的方法！
This unsettled existence is the very blood of science.
Science needs to fail to move forward. Theories
need to break down; their limits need to be exposed.
As tools probe deeper into Nature, they expose the
cracks of old theories and allow new ones to emerge.
However, we should not be fooled into believing that
this process has an end.
( Marcelo Gleiser, The Island of Knowledge:
The Limits of Science and the Search for Meaning )
It is imperative in science to doubt;
it is absolutely necessary, for progress in science,
to have uncertainty as a fundamental part of your
inner nature. To make progress in understanding,
we must remain modest and allow that we do not
know. Nothing is certain or proved beyond all doubt.
You investigate for curiosity, because it is unknown,
not because you know the answer. And as you
develop more information in the sciences, it is not
that you are finding out the truth, but that you are
finding out that this or that is more or less likely.
That is, if we investigate further, we find that the
statements of science are not of what is true and
what is not true, but statements of what is known
to different degrees of certainty…Every one of
the concepts of science is on a scale graduated
somewhere between, but at neither end of,
absolute falsity or absolute truth.
( Richard Feynman )
以上是從理論的層面來看科學，但從應用的層面來看又如何呢？
The empirical basis of objective science has thus
nothing “absolute” about it. Science does not rest upon
solid bedrock. The bold structure of its theories rises,
as it were, above a swamp. It is like a building erected
on piles. The piles are driven down from above into
the swamp, but not down to any natural or “given”
base; and if we stop driving the piles deeper, it is not
because we have reached firm ground. We simply stop
when we are satisfied that the piles are firm enough
to carry the structure, at least for the time being.
( Karl R. Popper, The Logic of Scientific Discovery, 1959 )
當我們明白
Just because we don’t know everything,
just because we cannot reach the ultimate truth
doesn’t mean that we don’t know anything.
我們就克服了「浮沙恐懼症」！
換句話說，愛智的人一方面必須具備自我批判熱誠，
全面及持久地投入他的觀察、實驗和思考，
而另一方面則必須和自己及任何人類思考的成果保持距離，
隨時再度審視，發展，修訂，甚至完全推翻以前的想法。
所以雨果說：「謹慎是智慧的長子」。
「誠實」honesty、「懷疑」skepticism 和「理性」reason
是哲學的信仰；
瞭解浮沙，接納浮沙，擺脫「浮沙恐懼症」的困擾，
是哲學入門的要求。
哲學家的工作就是「問問題」；
哲學從問問題開始，亦以問問題終結，
而我們得著的，就只是頭尾兩個問題中間解決了的東西。
哲學家從來不會期望一步登天，
而且登天是永遠沒有可能的事，
哲學家只是期望能夠一步一步地「迫近真理」。
Between absolute ignorance and absolute wisdom,
there is a place for knowledge and for progress.
( Andre Comte-Sponville )
The important thing is not to stop questioning.
( Albert Einstein )
The one real object of education is to have a man
in the condition of continually asking questions.
( Bishop Mandell Creighton )