150 Three Source Incompatibilist Arguments
not exercise voluntary control in the production of all of their motivational and
other action- generating states and processes. That they could exercise such
control over all such internal ingredients causally antecedent to an action would
be too stringent a requirement on freedom and responsibility. Accordingly, to
capture a plausible sense of ultimacy for free acts, it cannot be that each con-
dition that brings about a free action is such that the agent is the ultimate initiator
of it. It must be instead that an agent voluntarily contributes some substantive
necessary condition to that action.
With these considerations in mind, consider the following proposal for an
incompatibilist formulation of ultimacy (McKenna, 2008d: 192):
U: An agent is the ultimate source of her action only if she voluntarily con-
tributes some substantive necessary condition, C, to that action such that
there are no sufficient conditions for the occurrence of the action that obtain
independently of her agency.Will this do? Not if Frankfurt- examples are consistent with an agent being the
ultimate source of her action, as source incompatibilists typically contend. Con-
sider any Frankfurt- example in which the neuroscientist’s device ensures that the
agent will perform an action if she does not do so on her own. So long as there is
a successful example in which there is such a factor independent of the agent’s
contribution C that ensures that she will performing that same act, a condition
like U will fail as a way to specify ultimacy.^5 What needs to be added is that any
sufficient condition for the occurrence of the action that obtains independently of
her agency is not also a sufficient condition of her actual contribution to C. So
here is a proposal that arguably avoids this problem:
U2: An agent is the ultimate source of her action only if she voluntarily con-
tributes some substantive necessary condition, C, to the conditions that actu-
ally bring about her action, and there are no sufficient conditions for her
actual contribution to C that obtain independently of her agency.We shall treat U2 as a satisfactory way of specifying an incompatibilist ultimacy
condition on directly free action.^6
We turn now to a first way of formulating an Ultimacy Argument.^7 Assume
that a person acts as she does when she is (allegedly) free due to her state of
mind at the time. She might act from passion, out of anger, on calm cool reason,
but whatever it is, her agency is engaged by virtue of features of her mental
economy. When she is in control, her mental life produces her actions in a non-
deviant fashion. Just to simplify matters (and for no other reason), suppose we
think of reasons on the classic Humean model as belief–desire pairs. If an agent,
Ann, acts to steal a loaf of bread, there is some combination of belief and desire
that is Ann’s reason why she so acts, a reason we can abbreviate as BD. If she is
morally responsible for stealing the bread, and if she acted freely in doing so,
then it seems that both her responsibility and her freedom are due to her reason,