☆ 批判精神是一種「鍥而不捨」的思考態度。
至於各式各樣的思考方法，只不過是批判思維的工具而已，
而批判思維所需要的思考工具 intellectual skills，
視乎所批判的課題而定。
只有「我的腦袋」才是伴隨一生的思考工具。
Truth can be like the sun or the moon
but it can also be hidden behind a curtain.
You have to find it out by effort.
( Jason Ling )
鍥而不捨，俗語叫做「打爛沙盤問到篤」；
鍥而不捨，是因為有些真理是隱蔽的，有些真理是隱蔽的；
理性無上限，沒有鍥而不捨的精神就難以接近真理。
Our proud theories are but temporary resting places
of the mind on the unending road to knowledge.
( L. Rosenfeld )
No, science is not just knowledge;
it is knowledge working for its living,
correcting itself, and adding to itself.
( R. Calder 1955 )
☆ 批判精神是一種「尋根究底」的思考態度。
批判精神要求所有對真理熱愛的人從根源開始去思考，
而從根源開始去思考往往需要批判我們所有的「假設」
assumptions and presuppositions。
All this worldly wisdom was once
the unamiable heresy of some wise man.
( Henry David Thoreau, Journals, 1840 )
The most important truths are likely to be those
which….society at that time least wants to hear.
( W. H. Auden )
否則我們的思考可能只是借用了別人的思考，
而自己卻從來都未曾深思和研究過就已經接受了。
一旦我們推卸培育個人思考能力的責任，並且將思考外判，
容許個人的腦袋成為了別人思想的遊樂場之後，
個人的批判思考能力就每況愈下，慢慢貶值。
所以中學裡學習「幾何」geometry 的時候，
每一條定理都需要每位學生從新證明一次，
是極之有道理的教學方式。
The fatal tendency of mankind
to leave off thinking about a thing
when it is no longer doubtful
is the cause of half their errors.
( John Stuart Mill )
Nature does not seem to care very much
whether our ideas are true or not,
as long as we get on through life safely enough.
And it is surprising
on what an enormous amount of error
we can get along comfortably.
( Randolph Bourne, Youth and Life, 1913 )
儒家提出的「格物致知」，和批判思維有相同之處。
「世間之物，無不有理，皆須格過。」(朱熹)
格物，是指窮究事物的道理；而所謂窮，
是指徹底、窮盡，鍥而不捨，尋根究柢的意思。
「若是窮得三兩分，便未是格物。
須是窮盡得到十分，方是格物。」
《朱熹。朱子語類卷第十五》
☆ 批判精神是對所有的結論「存疑」。
所有的結論都是暫時性的結論，
隨時在新證據的出現之後需要重新批判。
Absolute certainty is a privilege of
uneducated minds — and fanatics.
It is, for scientific folks, an unattainable ideal.
( C. J. Keyser )
Ah！ don’t say you agree with me.
When people agree with me,
I always feel that I must be wrong.
( Oscar Wilde, 1891 )
From a worldly point of view,
there is no mistake so great as
that of being always right.
( Samuel Butler )
Believe those who are seeking the truth.
Doubt those who find it
( Andre Gide )
在真理面前，我們明白甚麼叫做「謙卑」humility。
The only wisdom we can hope to acquire
Is the wisdom of humility : humility is endless.
( T.S. Eliot )