NORMATIVE FORCE AND THE POSSIBILITY OF ERROR: A REPLY TO DOUGLAS LAVIN
0. Introduction
Any account of the normative force of practical reason must account for the received
distinction between rational and mechanical force. It is a philosophical platitude that
there is a difference between an agent’s responsiveness to reason and the workings of a
machine, and it is only when we are subject to rational rather than mechanical force that
we can be held responsible. This distinction is often understood in terms of a requirement
that normative, but not mechanical, force leave open a possibility of error. That is, it is
often thought that the difference between mechanical and normative (or rational) force is
that it is possible to violate the latter kind of rules, but not the former. In his 2004 piece
“Practical Reason and the Possibility of Error,”1 Douglas Lavin takes up the thought that
a complete account of normative force must leave open the possibility of error. He calls
this requirement the “error constraint.” In particular, Lavin argues that any account of the
normative force of practical reason must leave open the possibility of a failure to comply,
lest we collapse the distinction between rational and mechanical force. He then concludes
that it follows from this that there can be no such thing as an essentially rational will –
that is, the requirement that normative force leave open the possibility of error precludes
the possibility of a being who can’t but will in accordance with the norms of practical
reason, but who is subject to them nonetheless. I propose to take up Lavin’s argument
more carefully. In particular, I propose to examine in some more detail precisely what
possibility of error is required by an account of the normative force of practical reason,
how this requirement might relate to the distinction between rational and mechanical
force, and whether or not it does in fact lead to the impossibility of a perfectly rational
will, as Lavin would have it. I conclude that the distinction between rational and
mechanical force does indeed require that we admit a certain kind of error, and that this
does indeed rule out the possibility of a certain kind of perfection, though these
conclusions are much narrower than the ones that Lavin advances. Let us now consider
Lavin’s argument in more detail.
I. The Possibility of Error
At the heart of Lavin’s argument lies the thought that the distinction between rational and
mechanical force requires that we allow for the possibility that we violate rational, but
not mechanical, rules. For Lavin, unless we leave open the possibility that we violate
rational (or practical) principles, we cannot maintain the distinction between normative
and mechanical force. In particular, he takes it to be an adequacy condition on a theory of
practical reason that it leave open the possibility of a distinctively practical failure to
comply with its dictates; it is always possible, he argues, that we are “imperfectly hooked
up”2 with a practical principle in a way that cannot be explained in terms of the
theoretical errors of having the wrong principle in mind, or of misunderstanding or
miscalculating how the world is. To be sure, these errors are also always possible, and
they may also result in actions that violate the dictates of practical reason. Moreover, they
may indeed be errors proper in the sense that we may well be mistaken for, say, taking
1
2
Ethics, 114:3, 424. Hereinafter “Lavin.”
Lavin, p.427.
this to be the relevant principle, or, say, taking that to be the way the world is; we are
indeed responsible not only for the successful execution of the actions required by
practical reason, but also for correctly divining its requirements. However, over and
above the possibility of practical defects resulting from these kinds of errors, Lavin takes
there to be a further, distinctively practical kind of failure that lies specifically in the
misuse of our practical faculties, and that can occur even when, theoretically speaking,
we have reasoned correctly.3 It is the possibility of this kind of error that Lavin takes to
be a condition on a complete account of practical reason.
More specifically, for Lavin, we must keep this possibility open on pain of
collapsing the distinction between rational and mechanical force. It is only because it is
always possible for us to practically fail, in addition to the possibility of reasoning badly,
that we can distinguish between agency and action, on the one hand, and, say, the
movements of the planets, the replication of a cell, the building of a beehive, and so on,
on the other. Absent the possibility of the relevant type of failure, there could be nothing
further to which we could appeal to distinguish between agential and mechanical activity,
and in virtue of which we can hold the agents, but not machines (or other objects in the
natural world) responsible for their actions. Hence the conclusion that the error
constraint, so construed, stands as a condition of adequacy on a complete theory of the
force of practical reason.
Finally, Lavin argues, it follows from this requirement that there can be no such
thing a perfectly rational will. In particular, he argues, the requirement that a theory of the
force of practical reason leave open the possibility of practical error forecloses the
possibility of an agent who can’t but will in accordance with the practical law, but who
we take to be subject to its authority nonetheless.4 So conceived, then, his account may
well rule out the possibility of a holy or divine will. If Lavin is correct to insist that there
is such a thing as a distinctively practical error of the kind described above, then he is
right to conclude that where there is a being for whom such an error is impossible, we
cannot say of such a being that she is subject to the authority of practical reason, or that
she can be held responsible in the relevant sense. This much follows immediately from
what has come before. But is he right to assume that such a creature is impossible? Is it
true that holding such a being accountable to the norms of practical reason would be like
holding a machine responsible? Can we really not say of such a being that she is subject
to the practical law, on pain of collapsing the distinction between normative and
mechanical force? Let us examine Lavin’s argument in more detail.
II. A Perfectly Rational Will
Lavin puts the intuition behind the impossibility of a perfectly rational creature as
follows.
3
Although he does not specify this, I take it that Lavin also intends to exclude vicious
acts as possible sources of error for the purposes of his error constraint.
4
Lavin actually extends his conclusion to exclude the possibility of a being with no
capacity for pleasure or desire, and one who, though she is not essentially perfect,
happens to get things right every time. I am suspicious of these extensions as well as his
narrower conclusion, discussed above. In the interest of brevity, however, I will set aside
my objections to these further conclusions.
No mere mechanism can be under a principle or follow a rule; such a thing might only be
the locus of mere regularity. But a would-be perfectly rational will – something whose
will is in a state of perfection and thus which can’t really go wrong – must amount to no
more than a strange sort of mechanism or automaton.5
He then continues, “the claim is that principles can be no more than ‘merely descriptive’
of a perfectly rational will, just as physical laws are no more than ‘merely descriptive’ of
the trajectories of asteroids and planets.”6 The thought here seems to be that where a
being cannot but will in accordance with the practical law in a way that makes a
distinctively practical error impossible, this being no longer stands in relation to these
principles as an agent does to reasons; instead, in such a case, principles are reduced to
mere descriptions of her activities, as physical laws might describe the motions of the
planets or the workings of a machine, and, whatever we might say about the force of
practical reason, we can agree that it can be distinguished from merely mechanical force.
My central worry with Lavin’s objection to the possibility of a perfectly rational
agent is this. It is not clear that where an agent cannot but will in accordance with the
practical law, we cannot properly say that she is not responsible or subject to it at all, and
that she is like a mere machine. Consider, for example, the rules of theoretical reason. It
might turn out that it is psychologically impossible for us to, say, believe p and not p (in
the same thought), or, say, it might be impossible for us to fail to take modus ponens to
be a valid rule of inference, and so on. If this were so, then we couldn't but follow these
rules of rationality. Nonetheless, it seems to me that we would still say that we are
judging well, or that we are rational when we deny contradictions or infer correctly. The
mere fact that we cannot but judge in accordance with these rules does not seem to render
them inapplicable in this context, nor does it exempt us from responsibility when we do.
Nor, further, is it sufficient to conclude that we are acting as mere machines. To put the
point slightly differently, we are happy to continue to say that we are properly subject to
the norms of rationality even though the possibility of violating them is an open question;
nothing about the impossibility of violating them seems to impugn their normative status.
It seems to me that we might say something similar about a perfectly rational will.
If the possibility of agents who cannot but judge in accordance with the rules of
rationality does not impugn the normative force or the rules of reason, then it seems that
the possibility of an agent who cannot but will in accordance with the rules of practical
reason does not undermine the normative force of the latter types of reasons either. Just
as the mere fact that a given event could not but occur is not sufficient to conclude that it
did not occur in accordance with a rule, nor is the mere fact that that we could not but so
will sufficient to conclude that we are not subject to the practical law. If there is a
relevant difference between thought and action, it does not seem to lie here. The
norm/mechanism distinction does not seem to rule out the possibility of a being who
cannot but will in accordance with the practical law.
This said, however, the possibility of at least one kind of error must indeed remain
open if we are to maintain the distinction between rational and mechanical force. This is
the possibility that, despite our best efforts, our attempts at compliance are foiled because
the world has interfered. That is, it is always possible that, even though I did all that I
5
Lavin, p.443.
id. explaining Korsgaard’s discussion in “The Normativity of Instrumental Reason,”
p.240.
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could do, my charity falls into evil hands, my kindness is interpreted as insult, my
helpfulness results in harm, and so on. In short, it is always possible that the world fails to
cooperate; the force of reason alone cannot rule out this possibility. In this respect, it
seems that Lavin is correct to insist on the possibility of a certain kind of error, namely an
error that results from the world going awry, despite my best plans. It also seems to be
true that any account of normative force must leave open the possibility of this kind of
error, on pain of mistakenly according to norms causal efficacy. Normative force cannot,
on its own, effect material compliance; the mere fact that the world ought to be a given
way is not sufficient to make it so, and any account of normative force that collapses this
gap does indeed collapse the distinction between normative and mechanical force.
Furthermore, this is a distinctively practical error in the sense that it is one that arises in
virtue of the distinctively practical nature of the norms in question. Insofar as these norms
set standards for the natural world, there is always a possibility that their demands are not
met.
Note finally that, the requirement that we leave open the possibility of this kind of
error does indeed rule out the possibility of a certain kind of perfect agent, namely, one
who can guarantee successful compliance with the practical law by mere force of will.
There can be no one for whom appreciation of the practical law alone is sufficient for
success. This follows immediately from the possibility of error requirement as conceived
above. If we take the possibility that the world fails to cooperate with our best-laid plans
to be a practical error, then it seems that a complete account of the force of practical
reason does indeed require that we leave open the possibility of a certain kind of practical
error. However, it is not clear that this is the kind that Lavin has in mind in advancing his
argument. This is because although the world going awry may certainly result in error in
the sense that it may well result in a failure to satisfy the requirements of the practical
law, and although this error may be a practical one in the sense that it is one that arises in
practice rather than through the exercise of our theoretical capacities, it is not necessarily
an error that we can attribute to the agent.
Recall that the possibility of error that must be left open by an account of the
normative force of practical reason is the possibility that, despite my best attempts,
success eludes me because of facts about the world that are beyond my control. Here,
however, we would not say that the error is mine; instead, where failure ensues even
though I have done all that I could do, we must conclude that I acted well. It is true that
my lack of success might cause us to doubt whether I did indeed do all I could do, and
whether my failure did truly arise through no fault of my own. This is especially so when
I have repeated failures, or when I frequently plead bad luck in the face of failure. But
this is just to say that we are often in doubt as to whether or not our initial conditions
hold; it is not to say that we ought to withhold praise when they do hold. Hence, the
requirement that we leave open the possibility that the world goes awry does indeed rule
out the possibility of a certain kind of perfection, namely, that of an agent who can
guarantee success by mere appreciation of the rules. This much does indeed follow from
considerations of the force of practical reason alone. However, it does not, on its own,
rule out the possibility of an agent who consistently does all that she can do to comply,
and this may be all that is needed in order to say that she has gotten things right. It thus
seems that the error constraint so construed is not on its own sufficient to rule out the
possibility of someone who always does well.
There is one final possible error that I can think of that Lavin might have in mind. He
might think that there is an additional source for error in action but not thought that
leaves open the possibility that I have willed correctly, and that doesn't amount to the
world failing to cooperate. He might think that there is a gap between willing an act and
doing all I can do to execute it. This gap leaves open a source for error in practical but
(perhaps) not theoretical reason, and any account of the force of practical reason that
rules out the possibility of this error treats the relationship between the will and action as
that of mere mechanism since it takes the mere fact of willing to guarantee action. This
error may well be the distinctive kind of practical error whose possibility Lavin is trying
to preserve. Errors of this type play a prominent role in discussions of practical reason,
most significantly in discussions of moral motivation. Moreover, it seems like the kind of
error that Korsgaard is after in her rejection of instrumental reason that Lavin takes as his
starting point. If this is right, however, what does it have to do with the possibility of a
perfectly rational will? Even if it is true that the mere fact of willing cannot guarantee
action, why does it follow from this that we must also rule out the possibility of a
perfectly rational will? It seems to me that it is only if we make the impermissible
assumption that the relationship between the will and action is guaranteed that this
inference to a perfect will can go through. But this assumption is precisely what Lavin is
denying.
More generally, however, must an account of the force of practical reason really
leave open the possibility of this error? Are we really treating the relationship between
will and action as that of mere mechanism if we rule it out? Is it right to assume that such
cases cannot be redescribed either as cases of my not willing or as cases of the world
failing to cooperate? Consider again the difficulty. The worry here is that where we take
the mere fact of willing to guarantee action, we are impermissibly according to the will
mechanical rather than normative force. But, as we have seen, the error we make when
we elide these two is to mistakenly attribute causal efficacy to normative principles. This
is a mistake since, as we have seen, the mere fact that a norm dictates how the world
ought to be is not sufficient to make it so; it is always possible that the world fails to
cooperate. If, however, this really is the problem with ruling out the possibility of doing
all I can do despite having willed the action, then it seems that this error can indeed be
redescribed as the world going awry. There is no new kind of error that arises here.
If I am correct in my analysis, then there is no special kind of practical error that
is required by consideration of the force of practical reason alone over and above the
possibility that the world fails to cooperate. As we have seen, however, this kind of error
need not always impugn our responsibility; where failure results from facts about the
world, my actions may yet be praiseworthy, or, at the very least, they may not be
blameworthy. If this is correct, however, it might seem that we have lost our grip on the
very thought that started this discussion, namely Korsgaard’s objection to Humeanism
that no theory of practical reason can rule out the possibility that we act irrationally. If, as
I have suggested, the only kind of error that we must leave open is one that can leave my
responsibility intact, then what are we to make of her suggestion that I might always act
irrationally? If all we can say is that the world has failed to cooperate, then how can we
attribute this error to me? In virtue of what might was say that I have acted irrationally?
This objection moves to quickly; we need not give up on Korsgaard’s point just
yet. Recall again her claim.7 She famously argues that the mere fact I am subject to a
reason cannot guarantee compliance. It is always possible that I fail to do as I ought, even
on pain of irrationality. Her worry is that by making the existence of reason dependent on
the existence of motivation or desire, Humean accounts of practical reason mistakenly
require that reasons have causal force. Her point here is that we may well have reason to
act independently of facts about our respective psychologies or our actions; the mere
existence of a reason need not effect material changes in the world, including
psychological ones. Nor, conversely, can we divine the existence of a reason just by
inspecting our psychologies; in this respect, she insists, reason and motivation can come
apart. My point here is that we may well describe such an error as the world failing to
cooperate; we need not appeal to any special error of the will in order to make
Korsgaard’s point, so conceived. Moreover, this particular error can be attributed to me,
or, more specifically, to my irrationality, since we take certain failures of the world – say,
e.g., my failure to execute certain actions given certain states of mind – to be failures in
my practical rationality. Again, we need appeal to nothing further than the possibility of
such an error in order to explain the normative force of practical reason.
Conclusion
If the foregoing analysis is correct, then it seems that Lavin is correct to insist that the
distinction between normative and mechanical force requires that we leave open the
possibility of error, and that this requirement does indeed rule out a certain kind of
perfect being. However, as I have tried to show, this is not quite the kind of perfection
that Lavin intends to rule out. At the very least, it seems that we ought to draw a narrower
conclusion about the impossibility of a perfectly rational being than the one that he
draws; not all kinds of perfection are excluded by the error constraint. Nonetheless, even
on this narrower account, I suggest that we can still account for the possibility of
irrationality that got this discussion off the ground.
See especially Christine Korsgaard, “Skepticism about Practical Reason,” Journal of
Philosophy 83 (1986): 5-26.
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