An Introduction to Evolutionary Ethics (21 page)

4.
Beatrice's death is harmful to Beatrice.

5.
Beatrice's death is harmful to all who care about Beatrice.

6.
Therefore, Jones
should not
have killed Beatrice.

This argument seems pretty convincing. We have someone who desires to kill another human being and does so. Surely Jones shouldn't have done what he did. But is the argument valid? That is, can we accept all the premises, but
deny
the conclusion?

Take a minute, fire up your imagination, and imagine a world in which it's
true
that Jones, who desires to kill Beatrice, kills Beatrice, but it's
false
that Jones shouldn't have done what he did. Can you think of a case?

In case your imagination is slow to fire up, here are three cases that show this argument is invalid: (a) Jones is trying to prevent Beatrice from killing him; (b) Beatrice is an enemy soldier on a battlefield, and she is threatening Jones' platoon; and (c) Jones, as a member of a state execution team, is executing Beatrice for raping and murdering five children. In all of these cases, the premises are assumed to be true, but it is at least arguable that the conclusion is false. At the very least, we can see that the conclusion is not
necessary
. That is, there's no contradiction in accepting the premises but denying the conclusion.

Suppose, however, we were to add to premises 1 to 6 above the following:

5a
Beatrice is innocent of any crime.

5b
Beatrice is not an enemy soldier.

5c
Beatrice is not attempting to kill Jones.

Would we be logically required to assert, then, that Jones
should not
have killed Beatrice? Well, what if, by some cosmic coincidence, the brake lines of Jones' car malfunction as Jones is approaching a busy intersection, an intersection that Beatrice, on foot, happens to be crossing? Despite his attempt to swerve, Jones nevertheless kills Beatrice. It would be highly dubious to say that Jones' action was wrong. And since events conspired against Jones, it would be beside the point to say that Jones shouldn't have done what he did.

Come on
, you say.
Let's not get cute.
Take this case: Jones wants to kill Beatrice, and so he picks up a gun and shoots her point-blank in the head. End of story. Surely we wouldn't say, under
these
circumstances, that Jones should have done this, that his action was not immoral. Surely this is a valid argument if there ever was one.

We have to be careful here. It's one thing to ask whether or not Jones' action is wrong. Pretty clearly it is. But it's another thing altogether to ask whether the argument to that conclusion is deductively valid. To say it is would be to say that asserting the premises but denying the conclusion amounts to a
contradiction
. It's not enough to produce premises that make the conclusion highly likely. That's not a valid argument. Consider this argument as an example:

1.
The chances that this lottery ticket will win tomorrow's drawing are 1 in 43,887,609,870.

2.
This is a non-fraudulent ticket.

3.
Therefore, this ticket will
not win
tomorrow's drawing.

Would it be a contradiction to accept the premises, but deny the conclusion? Not at all. As the holder of this ticket, you might be accused of being a hopeless optimist if you doubted the conclusion, but you aren't
contradicting
yourself. It's of course very, very,
very
unlikely that your ticket will win, but it's not guaranteed to lose. After all, if your ticket does win, what do we say? That the universe suddenly contradicted itself? The lesson here is that, in determining whether an argument is valid, it must be the case that the premises make the conclusion
necessary
, that there is no possibility whatsoever of the premises being true but the conclusion false.

Returning to our revised example involving Jones, we can see that accepting the premises but denying the conclusion is not a contradiction, even though it might seem highly unlikely that Jones' action is
not
wrong. It's not like asserting that all humans are mortal and Beatrice is human but
denying
that Beatrice is mortal. That's not merely unlikely, that's impossible! In Jones' case, we cannot be guaranteed that some highly remote possibility may undermine the conclusion. But even setting aside exotic cases, we must not confuse asserting a contradiction and doubting what seems morally obvious. We might accuse someone who doubts the wrongness of Jones' action of being morally obtuse or excessively cautious. But that's not the same as accusing them of making a logical error: someone who denied Beatrice's mortality (despite accepting the facts that humans are mortal and Beatrice is human) would be making a logical error.

To get as much traction on this issue as possible, step back and think about what you are saying when you say: “Jones should
A
.” (Replace
A
with an activity of your choice:
eat chocolate cake
,
play badminton
,
keep his promise
.) In saying that Jones should
A
you recognize, at least implicitly, that this is entirely compatible with Jones
not A-
ing – whether it be in the past or now. In fact, saying that Jones should
A
is compatible with Jones never ever
A-
ing – as long as Jones lives. But you could still stick by your judgment. You might still insist that Jones should
A
. The reason is that utterances like “Jones should
A
” express a very particular kind of relation between, in this case, Jones and
A-
ing: it's a
recommendation
or a
command
. It's already accepted that this is not the way things are now (after all, if Jones kept his promises, there would be no need to insist that Jones keep his promises, right?). But what does this mean? It's means that saying how things
are
, as a matter of fact, is fundamentally different from saying how things
should
be. But if this is true, then is it any wonder that saying only how things are does not logically entail how things should be? Extending this idea further, it seems we could know everything about how the world is, but still not know how the world ought to be. Knowing how things ought to be requires more than just a grasp of (true) descriptions; it requires a grasp of
prescriptions
.
¹

7.2 You Can't Get Out What You Don't Put In So does all this mean that there can't be deductively valid moral arguments? It might seem like that's the conclusion to draw from all this. But it's not. As I'll show presently, constructing deductively valid arguments is actually quite simple. In one sense, the solution was there all along. Consider:

1.
No one
should
ever deliberately kill another innocent human being.

2.
Beatrice is an innocent human being.

3.
Therefore, no one
should
deliberately kill Beatrice.

Take a minute to consider the premises. Admittedly, premise (1) is a pretty blunt instrument. It doesn't, for example, discriminate between soldiers and civilians. But, for the sake of the argument, imagine that it's true. And imagine that Beatrice is in fact innocent. Can you imagine a case in which (1) and (2) are true, but the conclusion is
false
? After a moment's reflection, you should see that that's impossible. So long as you accept the premises (and don't change the meaning of the words), it should be clear that the premises make the conclusion
necessary.

How did we pull this off? What was missing in our earlier moral arguments that prevented us from deriving a logically necessary conclusion? The answer is clear: in our earlier attempts, none of the premises asserted what
should
be the case; they merely asserted what
is
the case. And that's the problem. Arguments that attempt to infer a “should” from purely “is” premises are invariably invalid. An argument that attempts to derive a “should” conclusion must contain at least one “should” premise. If you don't put one in, you can't get one out. As we saw above, there appears to be a fundamental gap separating asserting what
is
the case from asserting what
should be
the case. And this gap implies that we cannot derive claims about what should be the case (e.g., Jones
should not
kill Beatrice) from claims
only
about what
is
the case (e.g., Beatrice's death would be harmful to Beatrice). To make such derivations, we need to add at least one claim about what should be the case (“No one should ever kill humans”).

Philosophers have come to describe this as the fact/value distinction. The world, apparently, contains facts and values – and one is not reducible to the other. One way of expressing a value is a prescription, a statement about what should or ought to be the case. This, according to the fact/value distinction, is distinct from expressing a fact, a statement about how things, as a matter of fact, are.

7.3 “Of the Last Consequence”

What does this have to do with the philosopher David Hume? (And what does this have to do with evolution? We'll get to evolution in the next section.) Well, we have Hume to thank for first noting this distinction between fact and value. In one of the great philosophical tracts of Western philosophy,
A Treatise on Human Nature
, Hume observes: In every system of morality, which I have hitherto met with, I have always remark'd, that the author proceeds for some time in the ordinary ways of reasoning, and establishes the being of a God, or makes observations concerning human affairs; when all of a sudden I am surpriz'd to find, that instead of the usual copulations of propositions, is, and is not, I meet with no proposition that is not connected with an ought, or an ought not. This change is imperceptible; but is however, of the last consequence. For as this ought, or ought not, expresses some new relation or affirmation, 'tis necessary that it shou'd be observ'd and explain'd; and at the same time that a reason should be given; for what seems altogether inconceivable, how this new relation can be a deduction from others, which are entirely different from it. (Hume 2009/1882: part 1, §1) In our terms, Hume recognized that statements of fact “are entirely different from” statements of value. And he was the first to note the illicit move from is-statements (or “copulations of propositions, is and is not”) to ought-statements. Though imperceptible, the move is “of the last consequence,” which is to say:
very important.

If true, “Hume's Law” would place a critical constraint on any future moral theorizing: to establish a claim about what you ought morally to do, you have to presuppose at least one
other
claim about what ought morally to be done. And to defend
that
claim, you have to presuppose
another
claim about what ought morally to be done. And so on. One implication of this seems to be that moral theorizing (to the extent that theorizing is possible) is going to be forever autonomous, that is to say, a field of study whose laws and connections must, in the end, remain within the sphere of value. This should immediately suggest consequences for Social Darwinism.

7.4 Blocking the Move from Might to Right Darwin expressed amusement at the idea that his theory entailed that “might is right.” It's not clear whether Darwin had Hume in mind here, but Darwin had certainly read Hume and was influenced by Hume's writings.
²
In any case, Darwin was echoing in his amusement the observation Hume had made a century before: describing how things are is not the same as saying how things
ought to be.
But there can be no doubt that others missed the distinction. Consider one of Spencer's more pointed critiques of the way the state intervenes on behalf of the less fortunate. And note his assumption about the direction of “the natural order of things”: Blind to the fact that under the natural order of things, society is constantly excreting its unhealthy, imbecile, slow, vacillating, faithless members, these unthinking, though well-meaning, men advocate an interference which not only stops the purifying process but even increases the vitiation – absolutely encourages the multiplication of the reckless and incompetent by offering them an unfailing provision, and
discourages
the multiplication of the competent and provident by heightening the prospective difficulty of maintaining a family. (Spencer 1851: 151) According to Spencer, those who would advocate stepping in to assist the “incompetent” are disrupting the “purifying process” that is natural selection. To achieve its highest state, its most evolved form, the human race ought to let natural selection follow its course, as merciless as it may seem. Nature knows best. This is the core of Social Darwinism. That, on this view, is how nature works – and it's a good thing. We saw in the last chapter, that nature does not work in that way. In many “near-possible worlds” natural selection does not purify (in the sense that Spencer meant); it contaminates. It produces creatures that are unfailingly cruel and unfaithful and lazy. English gentlemen are not at all the inevitable product of evolutionary forces.

But even if we set this aside, even if Spencer got that part right, he fell afoul of Hume's Law when he tried to infer, from those premises alone, that that's how things ought to be. Suppose it's true that natural selection tends, as a matter of fact, to produce humans who are fair and industrious. Suppose natural selection, left to its own devices, tends to eliminate those who do not show generosity or kindness. Suppose natural selection works toward a species that realizes, as far as possible, social harmony. Suppose all this is true. Suppose, that is, that that is how things are and how things have been. All of our efforts in this chapter have been aimed at
blocking
the move from these premises (alone) to: we
ought
to be fair and honest, generous and kind; we
ought
to promote social harmony. So long as the Social Darwinist does not include among the premises an ought-claim (or normative claim), none of these ought-claims follows. According to Hume, “a reason should be given … how this new relation can be a deduction from the others.” With no such reason offered, the Social Darwinist does not close the gap.