我們時刻都會相信很多東西：從「我面前有部電腦」，到「民主社會比其他政制優勝」。
我們說理性者當根據充分證據相信，然而我們有沒道德責任如此做？
(也就是說，一個人不根據充分證據相信，至少有時是不道德的。)
以下是本人在讀哲學碩士「科學與理性思考」課程時，期末論文的一部份的答案，評論以上問題。
本文主要評William Clifford 1877年的文章"Ethics of Belief"[1]和William James 1896年的文章"The Will to Believe"[2]，他們有十分兩極的立場。
本文只有英文版本。
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問題：
"4. According to William Clifford, “it is wrong always, everywhere, and for anyone, to believe
anything upon insufficient evidence.” Do you agree with Clifford’s principle? Why or why not?
Do you think that William James’ responses in “The Will to Believe” are reasonable and sound?
Why or why not?"
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答案：
In this essay, I will evaluate William Clifford’s evidentialism
[1] and William James’ opposition [2]. I shall state why they are both erroneous,
then I will propose a more moderate form of evidentialism.
1. On
Clifford’s Arguments
1.1 Strengths
of Clifford’s Arguments
Clifford claimed that “It is wrong always, everywhere, and for anyone, to believe anything
upon insufficient evidence.” (Clifford’s Principle) [1]
Clifford argued for his principle from the
consequences of belief. He said that “no
one man’s belief is in any case a private matter”, they all are “stored up for the guidance of the future”.
[1] He thought that, not only beliefs affect immediate actions, but also contribute to our habits of forming belief. Therefore we have responsibility to make
sure our beliefs are true.
There are often news in which parents starve their
children with vegan diets [3][4], and there are people who believe in
“sorcerers” who are actually frauds. [5] We have a plenty of examples of
beliefs that first seem innocent but later became harmful to oneself or others.
It thus seems great care should be taken in forming even our most private
beliefs.
In the story of the ship owner, Clifford stressed
that even if the ship did return safe, its owner is still guilty. He argued
this from the possible bad consequences of the habit of believing based on insufficient evidence. Just like one is
guilty for careless driving, though we may not intentionally harm people, if we
know the possible bad consequences, we are still guilty for taking our beliefs
too lightly.
1.2 Weaknesses
in Clifford’s Arguments
The first problem of Clifford’s Principle is that it
is too demanding to be useful in guidance. In Clifford’s Principle, anyone is required to seek sufficient
evidence on anything.
Most people should agree that if one cannot do something, she is not obliged in doing so (the “ought implies can” principle). Thus Clifford’s
Principle cannot be applied to people who do not have the mental ability to base
their beliefs on sufficient evidence. These include young children, people that
are too old, and the mentally impaired.
Even to other people Clifford’s Principle is still
too demanding. For our lives will be paralyzed if we require our every belief
to be based on sufficient evidence. E. g. At supermarket, I decide to buy some
milk because I remember that my home has run out of it; if I demand for sufficient
evidence, I may need to go home and double-check. We simply do not have time to
acquire sufficient evidence for every little thing; doing so is impractical.
Psychologist Daniel Kahneman suggests that we have
two cognitive systems of making decisions: System 1 is faster than System 2 but
also more easily makes mistakes. [6] System 2 is more evidence-based. However,
System 1 is also important and is mostly used on urgent and relatively
unimportant things.
The Clifford’s Principle is also theoretically
impossible. To demand sufficient evidence for a belief needs to presume another
belief. E. g. believing that it has just rained because the street is wet,
requires the belief that when it rains, it always makes the floor wet. If we
continue to ask for sufficient evidence for the presumed beliefs, then either
we are caught in an infinite regress, or at some point we cannot find evidence
for some beliefs. Philosopher Ferdinand Schiller suggested that in science
there inevitably are beliefs that cannot be verified by evidence such as
uniformity of nature and causality. [7]
2. On
James’ Arguments
2.1 Strengths
of James’ Arguments
William James provided four (supposedly) jointly
sufficient conditions under which we are justified to believe without evidence:
(1) there is no evidence for or against the proposition; the option is (2)
living (we are willing to believe), (3) forced, and (4) momentous (important).
The third condition (“forced”) fits well to the
existential condition. When Sartre said “if
I do not choose, that is still a choice” he was talking about the choice
for how to live our lives. [8] If true, the choosing is really forced upon each
of us. If further there is no evidence to help us in making such choices, we
can only take a “leap-of-faith”.
James further named two instances in which
evidentialism can be violated:
(A) Hypothesis
venturing (evidence available only after we believe in it)
(B) Self-fulfilling
beliefs (the belief is true if we believe in them)
Though (A) is problematic, (B) is interesting. We
can actually find examples which support it. E. g. If everyone believes “courtesy
is beneficial to all”, and acts according to it, then the community can indeed
become more orderly and harmonious.
2.2 Weaknesses
in James’ Arguments
While condition (1) and (3) may be sufficient to
justify some cases of violating evidentialism, other conditions (living,
momentous) seem unnecessary or even irrational. For it is not clear what counts
as “living” options. It seems arbitrary and irrational to dismiss a proposition
simply from our own feeling or the time we live in. (James referred to Greek
mythology as a “dead” option)
Furthermore, for “hypothesis venturing”, James did
not give example in which evidence is available only after one starts to
believe. We must be very careful this is not an instance of confirmation bias in psychology (that we
tend to find evidence in agreement with our belief). If we seek “hypothesis
venturing”, we risk trapping ourselves in false beliefs.
Another problem for James’ thinking is that it separates
belief from truth and knowledge. To say that “I believe in X” where X is a
proposition normally means “I think X is true”. But James’ conditions (1-4) has nothing to guarantee truth or
knowledge. It seems to be an abuse of the word “believe”.
In “The Will to Believe”, James wanted to justify his
own Christian belief without sufficient evidence. He dismissed Clifford’s
proposal of suspending judgement, claiming that religious belief is a “forced”
one. But it can hardly be seen how: many people have never heard of
Christianity before death; not deciding on a particular religion seems fine. Moreover,
many beliefs in Christianity may have evidence against it (e. g. the Earth is old), so religious beliefs may not
fit with James’ conditions.
3. A
Moderate Evidentialism
There is still one more question: why is it better we base our beliefs on evidence?
For finding truth? Some may think that truth leads to better wellbeing of
people (argued in “The Ethics of Belief”). So thinking based on evidence is
moral in a consequentialist sense.
But there may be another reason. A Robert Nozick’s thought
experiment can be used to justify that truth has intrinsic value: though we may
be happier in a virtual world, we still want to live in reality. [9] Likewise,
knowing the truth by means of evidence is of high value.
With considerations of what I mentioned in Section 1, 2 and
above, we should always try our best to actively seek and believe on sufficient
evidence when (1) there is available
evidence; and that the issue (2) is significant
and (3) is not urgent.
“Trying our best” takes into account different mental capabilities,
while encouraging a healthy habit of practicing rational thinking. Condition
(1) also avoid the intuitive beliefs such as that of causality, where no
evidence is possible.
In other cases, not considering all available evidence is not
a vice, because in those cases considering all available evidence is either impossible
or impractical (e. g. on insignificant things).
I have reviewed the strengths and weaknesses of the arguments
of Clifford and James on ethics of belief. Clifford’s Principle is too
demanding and is impossible practically and theoretically; James’ conditions
are questionable and have twisted the meaning of epistemological belief. I
proposed a moderate version of evidentialism: we should always try to believe
on sufficient evidence when the issue is significant and is not urgent.
Q4: (Ethics of Belief)
[1] Clifford, W. K.
(1877). The Ethics of Belief. The Contemporary review, 1866-1900, 29, 289-309.
https://people.brandeis.edu/~teuber/Clifford_ethics.pdf
[2] James, W.
(1896). The will to believe: An address to the philosophical clubs of Yale and
Brown Universities. New World, 1878-1899.
http://krypton.mnsu.edu/~jp6372me/THE%20WILL%20TO%20BELIEVE%20.pdf
[3] Alex Chapman For
Daily Mail Australia. (2018, December 25). Sydney vegan parents kept their
malnourished daughter off the grid. Retrieved from
https://www.dailymail.co.uk/news/article-6528669/Sydney-vegan-parents-kept-malnourished-daughter-grid.html
[4] Mikelionis, L.
(n.d.). Vegan parents charged after starving their baby by switching from
formula: Police. Retrieved from
https://www.foxnews.com/us/vegan-parents-charged-after-starving-their-5-month-baby-by-switching-from-doctor-advised-organic-formula
[5] 香港01.
(n.d.). 【性交轉運】案情全記錄：占卜師脫罪當庭灑淚 曝光大量猥褻相片成關鍵.
Retrieved
from https://www.hk01.com/issue/202/性交轉運案專頁-占卜師脫罪當庭灑淚-曝光大量猥褻相片成關鍵
[6] Kahneman, D.,
& Egan, P. (2011). Thinking, fast and slow (Vol. 1). New York: Farrar,
Straus and Giroux.
[7] Schiller, F.C.S.
(1903) "Axioms as Postulates", p. 111
[8] Sartre, J. P.
(2007). Existentialism is a Humanism. Yale University Press.
[9] Nozick, Robert
(1974). Anarchy, state, and utopia. New York: Basic Books. pp. 42–45.
