人禽之別幾希？
人類獨特的心靈？
St. George Jackson Mivart: non-human animals might
have bodies similar to ours, but our minds remain
something special.
“There is no fundamental difference between man and
the higher mammals in their mental faculties.”
(Darwin)
The pattern of Darwin’s argument
First, he gives a large number of examples of animal
behavior, designed to overwhelm the reader with evidence
that animals do in fact have instincts that operate for the
good of the community.
Then he argues that this not surprising, but is precisely what
one would expect on the hypothesis of natural selection.
Along the way he protests the inconsistency of our
unwillingness to attribute morality to the animals, when we
would so characterize men for essentially the same behavior.
And finally, he offers an account of how the distinctive
features of human morality could have evolved from nonhuman beginnings.
理性能力
“Of all the faculties of the human mind, it will, I
presume, be admitted that Reason stands at the summit.
Few persons any longer dispute that animals possess
some power of reasoning. Animals may constantly be
seen to pause, deliberate, and resolve. It is a significant
fact, that the more the habits of any particular animal
are studied by the naturalist, the more he attributes to
reason and the less to unlearnt instincts.”
“So many facts have been recorded in various works showing that
animals possess some degree of reason, that I will here give only two
or three instances, authenticated by Rengger, and relating to
American monkeys, which stand low in their order. He states that
when he first gave eggs to his monkeys, they smashed them and thus
lost much of their contents; afterwards they gently hit one end against
some hard body, and picked off the bits of shell with their fingers.
After cutting themselves only once with any sharp tool, they would
not touch it again, or would handle it with the greatest care. Lumps of
sugar were often given to them wrapped up in paper; and Rengger
sometimes put a live wasp in the paper, so that in hastily unfolding it
they got stung; after this had once happened, they always first held the
packet to their ears to detect any movement within. Anyone who is
not convinced by such facts as these, and by what he may observe with
his own dogs, that animals can reason, would not be convinced by
anything I could add.”
人禽之別：moral sense
“Of all the differences between man and the lower
animals, the moral sense is by far the most important.”
Darwin: non-human animals have the same capacities
that form the basis of morality in humans; although in
non-humans those capacities are not so well developed.
Social Instincts
Evidence of sociability in animals: their living in
groups and their apparent need for one another’s
company.
“Everyone must have noticed how miserable horses,
dogs, sheep, etc. are when separated form their
companions; and what affection at least the two former
kinds show on their reunion.”
“Social animals perform many little services for each
other: horses nibble, and cows lick each other, on any
spot which itches: monkeys search for each other’s
external parasites.”
Social instincts (不求回報的利他行為)
“Capt. Stansbury found on a salt lake in Utah an old
and completely blind pelican, which was very fat, and
must have been long and well fed by his companions.
Mr. Byth, as he informs me, saw Indian crows feeding
two or three of their companions which were blind.”
Social instincts (不求回報的利他行為)
“Brehm encountered in Abyssinia a great troop of baboons
which were crossing a valley: some had already ascended the
opposite mountain, and some were still in the valley; the
latter were attacked by the dogs, but the old males
immediately hurried down from the rocks, and with mouths
widely opened, roared so fearfully, that the dogs quickly
drew back. They were again encouraged to the attack; but by
this time all the baboons had reascended the heights,
excepting a young one, about six months old, who, loudly
calling for aid, climbed on a block of rock, and was
surrounded. Now one of the largest males, a true hero, came
down again from the mountain, slowly went to the young
one, coaxed him, and triumphantly led him away—the dogs
being too much astonished to make an attack.”
Altruism in Rhesus Monkeys
Altruism might be defined simply as action that is
motivated by the desire to help others. However, we
may also use the word in a somewhat stronger sense, as
involving the willingness to forgo some good for oneself in
order to help others.
Understood in this stronger way, altruism is often
taken to be the paradigmatic moral trait. But is
altruism, in this sense, exclusively a human
characteristic? Or do other animals also possess this
quality?
A series of experiments conducted at the Northwestern
University Medical School and reported in the
psychological journals for 1964: these experiments were
designed to discover whether rhesus monkeys are
altruistic, and the method was to see whether they
would be deterred from operating a device for securing
food if doing so would cause pain to another monkey.
One animal (called by the experimenters the “operator”
or “O”) was placed in one side of a divided box and
taught to obtain food by pulling either of two chains.
Food was available only when a light signal was given (a
different light for each chain), and the O was trained to
show no special preference for either chain.
Another monkey (called the “stimulus animal” or “SA”) was
put into the other side of the box, which was divided by a
one-way mirror so that the O could see the SA but not the
other way around. The floor on the SA’s side was covered
with a grid attached to a shock source. Three days were
allowed for the O to adapt to the presence of the SA, and
then a circuit was completed so that whenever the O pulled
one of the chains to secure food the SA received a severe
electrical shock. Pulling the other chain continued to give
food, but produced no shock. Now, by turning on one
signal light at a time, in various sequences and at various
intervals, the experimenters could determine the extent to
which the perception of the SA’s distress would influence
the O’s willingness to pull the shock-producing chain.
After numerous trials the experimenters concluded that “a
majority of rhesus monkeys will consistently suffer hunger
rather than secure food at the expense of electroshock to a
conspecific”. In particular, in one series of tests, 6 of 8
animals showed this type of sacrificial behavior; in a second
series, 6 of 10; and in a third, 13 of 15. One of the monkeys
refrained from pulling either chain for 12 days, and another
for 5 days, after witnessing shock to the SA—which means
they had no food at all during that time.
These experiments seem to show the rhesus monkeys are
altruistic in the strong sense—that they will sacrifice their
own good for the sake of others.
Some worries
Was the O’s reluctance to pull the shock chain
correlated with relative positions in a dominance—
submissiveness hierarchy?
Did differences in sex have any effect?
Reply to worry 1
Relative dominance was determined when the animals
“were paired against each other in another apparatus and
required to compete for 100 grapes presented one at a time.
In most cases dominance was quickly established, the
dominant animal getting 90 percent of the grapes.”
The experiments were then divided into those in which the
dominant animal was the SA and the submissive animal was
the O; those in which the roles were reversed; and so forth.
And it was found that this made no difference to the
outcome.
Reply to worry 2
Experiments showed it made no difference whether the
O was male and the SA female; whether they were both
male; and so forth.
Additional evidence for the ascription of altruism
The experimenters found that animals who had
previously been SAs were significantly more reluctant
to pull the shock chain when they were made Os than
animals who had not been SAs themselves.
The explanation suggested by the hypothesis of
altruism is that these animals were more reluctant to
pull the chain because, having suffered the shocks
themselves, they had a more vivid comprehension of
what it was like, and so a greater reluctance to see
someone else in the same position.
Additional evidence for the ascription of altruism
It was also found that Os who had been cage-mates of
their SAs were more reluctant to pull the shock chain
than Os who had not been cage-mates of their SAs.
Again, this is just what we would expect if we take our
common knowledge of human beings as our model: we
are less willing to harm someone we know than we are
to harm strangers.
Special moral capacities of human beings
Despite his concern to demonstrate continuities
between human and animal life, Darwin does not
argue that non-humans are moral agents in the same
sense as humans: there are obviously differences
between the moral capacities of humans and nonhumans, and Darwin does not deny it. Instead, he sets
himself to explain what those differences are and why
they exist.
Darwin’s notion of morality
Darwin: when ethics is viewed from the perspective of natural
history, we find reason to reject the opinion of some philosophers
that “the foundation of morality lay in a form of selfishness.” It is
the social instinct, and not the instinct for self-preservation, that
forms its basis.
Therefore, Darwin says, those philosophers who have advocated
“the Greatest Happiness principle” are closer to the mark—
although he thinks it would be better to speak of “the general
good or welfare of the community, rather than the general
happiness.” (The latter, in his opinion, is too restricted a term.) Of
course, Darwin believed that the social instincts arise only because
the drive for self-preservation is more fundamental. But morality
comes into existence only with the social instincts. Hence
Darwin’s insistence that “the Greatest Happiness principle” more
aptly expresses the basic moral rule.
Darwin’s notion of morality
Darwin assumes that moral behavior promotes the
general welfare, but he also stresses that a moral agent
is an individual with a conscience—a sense of duty—not
unlike that envisioned by Kant.
The two notions are wedded by Darwin’s assumption
that a person of conscience will standardly approve of
behavior that promotes the general welfare.
The task he sets himself is to explain, compatibly with
the principles of natural selection, how humans could
have come to be moral agents of this sort.
Reason and the acquisition of moral knowledge
Human morality is the product, not just of the social
instincts, but of the the social instincts plus
intelligence.
Thus, on Darwin’s view, the higher stages of morality
emerge with the development of the higher rational
capacities: “Any animal whatever, endowed with wellmarked social instincts, would inevitably acquire a
moral sense or conscience, as soon as its intellectual
powers had become as well developed, or nearly we
well developed, as in man.”
智力如何促進道德？
“The social instincts which no doubt were acquired by
man, as by the lower animals, for the good of the
community, will from the first have given to him some
wish to aid his fellows, and some feeling of sympathy.
Such impulses will have served him at a very early
period as a rude rule of right and wrong. But as man
gradually advanced in intellectual power and was
enabled to trace the more remote consequences of his
actions; as he acquired sufficient knowledge to reject
baneful customs and superstitions…so would the
standard of his morality rise higher and higher.”
Conscience
18th century Britain produced a distinguished group of
moral philosophers, including such figures as Lord
Shaftesbury, Joseph Butler, and David Hume. The idea
of a “moral sense”, or conscience, was prominent in
their thinking, but they gave the notion a decidedly
naturalistic interpretation.
To have a moral sense was to have a capacity for
second-order attitudes—attitudes that have one’s other
attitudes as their objects. This, they thought, was what
makes man a moral agent in a sense in which other
animals are not.
Can dogs have conscience?
A dog’s attitudes (they said) are all directed at objects
external to the dog himself: he desires food, he desires
what will make him warm, he desires to avoid the
sources of pain. Perhaps, they might have said if they
had known more about altruism among the animals, a
dog might even desire that other dogs should not suffer.
But the dog cannot desire to have a certain attitude,
and he cannot regret that he has certain attitudes.
A man, on the other hand, can want something (I want
to hurt the person who hurt me) and at the same time
can regret that he wants it (I disapprove of myself for
wanting revenge, and wish that I had a more generous
temperament).
It is this capacity for approving or disapproving of one’s
own attitudes that constitute one’s conscience.
In Darwin’s notebooks for 1838-40 there are numerous
references to these thinkers, and Darwin’s own
treatment of conscience, elaborated years later in The
Descent of Man, is similar to their treatment.
But Darwin thought that the very existence of
conscience is puzzling: how can there be such a thing?
Conscience, as Darwin conceives it, is a phenomenon
closely associated with conflict situations.
Facing a choice about what to so, a man may be pulled in
different directions by conflicting “natural impulses”. For
example, there may be a danger that he can avoid by
running away and he may be afraid; or, there may be food
that he can seize, and he may be hungry. At the same time,
running away from the danger or seizing the food may be
contrary to the interests of the community at large, and
because he has “social instincts” he is disinclined to do
those things. So whatever he does, he will be going against
one or another of his natural impulses.
Suppose, then, his fear or his hunger wins out, and he
acts contrary to the general welfare of the community.
Later, when he reflects on what he has done, he feels
bad about this, and regrets it. This is the deliverance of
conscience; it is the wish that one, rather than another,
of one’s attitudes prevailed.
Puzzle
Darwin found this puzzling because it seemed strange that
one sort of “natural impulse”—the social instincts—should be
thought better or more worthy of respect than any other.
Why, in retrospect, are we uncomfortable with the fact that
we acted on some instincts rather than on others, when they
all equally “natural”?
As Darwin put it, “Why does man regret, even though he
may endeavor to banish such regret, that he has followed the
one natural impulse, rather than the other; and why does he
further feel that he ought to regret his conduct? Man in this
respect differs profoundly from the lower animals.”
Two solutions
The 18th century moralists had considered two general
solutions to this problem:
First, we can distinguish between the strengths of the various
impulses to action. Perhaps the social instincts are simply
stronger than the others, so that when the man regrets
giving in to fear or hunger the regret is produced by the
superior strength of the social impulse.
This sort of explanation, however, does not seem to work. If
the social impulse is stronger than fear or hunger, then why
he did not act on it originally?
nd
2
solution
This sort of consideration led Butler to distinguish the
strength of conscience from its authority. He held that the
various springs of action form a natural hierarchy, with
conscience at he top, so that conscience has a supremacy
that does not depend on its strength.
Thus, even if an individual constantly acts contrary to
conscience because his conscience is weak, while his other
impulses are strong, his conscience still dictates what he
ought to do because that is its natural function.
Darwin, however, regarded this as so much hocus-pocus,
and sought a less exotic explanation.
“Butler and MacIntosh characterize moral sense by its
‘supremacy’—I make its supremacy solely due to greater
duration of impression of social instincts, than other
passions, or instincts.”
It was this notion of ‘greater duration’ that was to
provide the key for Darwin’s explanation.
Darwin’s account
Suppose a man does something , out of fear or hunger, that
harms the community. Then he reflects on what he has
done. Now the social instincts are permanent, and persistent;
but particular desires come and go. Therefore, when he
reflects on his past conduct, his social instincts are still with
him, but the particular desire that, at the time of action,
overwhelmed the social instincts, is fading away. Thus he
regrets what he did. This after-the-fact reflection is what we
call ‘conscience’, and the fact that the social instincts are
stronger at the time of reflection, even if they were not
stronger at the time of the action, explains why such
reflection results in their endorsement.
“Thus, as man cannot prevent old impressions continually passing
through his mind, he will be compelled to compare the weaker
impressions of, for instance, past hunger, or of vengeance satisfied or
danger avoided at the cost of other men, with the instinct of sympathy
and good-will to his fellows, which is still present and ever in some
degree active in his mind. He will then feel in his imagination that a
stronger instinct has yielded to one which now seems comparatively
weak… At the moment of action, man will no doubt be apt to follow
the stronger impulse; and though this may occasionally prompt him
to the noblest deeds, it will far more commonly lead him to gratify his
own desires at the expense of other men. But after their gratification,
when past and weaker impressions are contrasted with the everenduring social instincts, retribution will surely come. Man will then
feel dissatisfaction with himself, and will resolve with more or less
force to act differently in the future. This is conscience; for conscience
looks backwards and judges past actions, inducing that kind of
dissatisfaction, which if weak we call regret, and if severe remorse.”
Admirable people
Completely admirable people: people’s social instincts are
strong enough to overcome the particular inclinations—fear,
hunger, etc.—which might otherwise lead them to act
contrary to the general welfare.
Not completely admirable people:
(1) those who yield to temptation but later regret it
(2) those who have no regrets (‘essentially bad’ people: their
social instincts are so weak, or even non-existent, that they
do not even control later reflections. These are the people
who have no conscience.)
Darwin: “If he has no such sympathy, and if his desires
leading to bad actions are at the time strong, and when
recalled are not overmastered by the persistent social
instincts, then he is essentially a bad man; and the sole
restraining motive left is the fear of punishment.”
How can there be such people? The natural
explanation, from the standpoint of natural history, is
that they are variations.
Moral progress
Despite his acknowledgement of the existence of conscienceless
men, Darwin was an optimist who believed, in good 19th century
fashion, that the human race is advancing towards ever greater
moral perfection.
His account of the nature of this progress, and of the conditions
of human life that make it possible, followed naturally from his
view about the role of reason in expanding the scope of the social
instincts.
He envisioned an ever-widening circle of moral concern, that
would spread beyond self and family to include neighbors and
countrymen and eventually all mankind. And the human social
instinct would go a step beyond even that, to include within its
sphere of concern the other animals as well.
As man became more rational and as his social
instincts were guided more and more by reason, “his
sympathies became more tender and widely diffused,
so as to extend to the men of all races, to the imbecile,
the maimed, and other useless members of society, and
finally to the lowered animals—so would the standard
of his morality rise higher and higher.”
Discussion
Is the difference between humans and non-human animals
in terms of social instinct a matter of degree?
Is the difference between humans and non-human animals
in terms of rationality a matter of degree?
Is Darwin’s account of conscience (well-marked social
instincts + advanced intellectual powers) plausible?
Does Darwin’s account succeed in naturalizing morality?
Is there anything distinctive about human morality?