If, for example, I bump a flower vase and it shatters on the floor, both a determinist and a libertarian can assuage my guilt by saying it wasn't my "fault." Accidents do happen. For the determinist, however, my bumping the vase is not a pure accident--far from it. Rather, on determinism, it was an inevitable occurrence derived from my total lower-level causal constitution at the moment I bumped the vase. It was a metaphysical necessity, but not my personal fault. "You didn't really break the vase," my determinist friend might explain, "your elbow did. It was bound to happen. Don't be too hard on yourself." Not I but my arm is to blame. On this it seems both the determinist and the libertarian can agree: not being a personal action, my bumping off (heheh) the vase does not belong in the realm of personal responsibility. (If, however, elbows and hard floors could be penalized...!)
Now suppose I aim a gun at my neighbor's house and fire a bullet, whereupon it kills my neighbor. Along come my determinist and libertarian friends, if not to assuage my guilt, at least to ascertain what happened. This time I am clearly to blame for my neighbor's death. Or so says my libertarian friend: "Your elbow didn't do it this time, you did. You've done a bad thing." Distressed, I turn to my determinist friend for some Lucretian counsel. "Did not," I ask, "my finger pull the trigger in the same way that my elbow bumped the vase? Wasn't my firing of the gun 'bound to happen' in the same way my bumping of the vase was? Why am I culpable now but not then?" I won't put words in his mouth, because I genuinely wonder what the determinist's appropriate reply ought to be.
Assuming, arguendo, that both my bumping the vase (and, not insignificantly, its falling to shatter on the floor), as well as my firing the gun (and, again, not insignificantly, its striking my neighbor), are wholly determined by antecedent causal conditions, what differentiates them in a morally significant way? How do we decide where along the total causal line of some event "my" responsibility comes in? Does the difference emerge if my volitional consciousness is added to an action? Seeing as I had no intention or desire to bump the vase (itself a wholly determined lack of volition), but that I did have a conscious desire or intention to shoot my neighbor (likewise a wholly determined volition), am I thus morally responsible for firing the gun but not for breaking the lamp? This sort of reply seems unsatisfactory for two reasons.
First, it seems that volition is not intrinsic to moral responsibility. Were I a truck driver, imagine that one night I negligently fall asleep while driving and crash into another car, killing the family of four inside. Certainly I had no volition to kill them, nor to fall asleep, but I am no less responsible for my negligence at the wheel. Recall that I had no volition to break the vase (and let's add that it was a priceless heirloom handed to my wife by her mother on her death bed, such that breaking it seems like a genuine moral failure on my part). Allegedly, my causally determined lack of volition in that case morally differentiates my bumping the vase from my causally determined firing of the gun plus a volition to murder. But my point now is that a presence of volition, determined or not, is not a necessary condition for moral culpability (such as falls to a negligent driver). Whence, then, arises the moral gravitas of crashing into a family on the road which bumping a vase lacks? Both events were, assuming determinism, wholly precipitated by antecedent causal factors, yet one is morally culpable, while the other is only dimly and analogously so. Volition is usually relevant to assigning guilt, but not intrinsically.
Second, my volitions, or lack thereof, were as deterministically incipient in the causal progression as were the events themselves. My volition to shoot my neighbor, that is, was just as deterministically incipient as the clutching of my finger around the trigger--and yet only the former is morally significant. Why? Indeed, my bumping the vase was just as deterministically incipient in its own causal sequence as shooting my neighbor was in its causal complex. Yet, only the latter is morally significant deterministic eventuality. Why? It seems that moral significance does not arise from the mere 'tightness' of causal antecedents prior to an event, otherwise both my bumping the vase and pulling the trigger would be equally deterministically "moral." Willing to shoot my neighbor and pulling the trigger--as well as the bullet's flight into his body--are equally determined eventualities, yet oddly I am only culpable when they are paired, not when they are determined separately. (I.e., if I were causally subjected to a desire to kill him but not causally subjected to pulling the trigger, I would not be culpable, and, presumably, were I only subjected to a random pull of the trigger, minus a subjection to a desire to kill, I would not be culpable.) Whereas my libertarian friend had said, "You've done a bad thing," I wonder if my determinist friend would be magnanimous enough to say, "A bad thing has been done by way of you."
What we have are four circumstantially 'quasi-events'--not-willing, bumping, willing, shooting--which mysteriously become moral only when determined in certain pairs. What accounts for this? There appears to be no morally significant difference between the incipient emergence of one event minus an emergent volition and another event that happens to have been paired deterministically with a volition. After all, the pairing or decoupling of volitions-and-actions is but a deterministic function of the larger causal sequence in which they occur. Just as my determinist friend consoled me that "accidents happen" (like bumping vases) and that it was "bound to happen," so he might console me in jail by saying that "volitions happen" and that my homicidal urge was "bound to happen." My homicidal intention--in whatever sense it could even be ascribed to me--is no more or less a brute causal 'efflux' of a deterministic world than my lack of such an intention, or my elbow's collision with a vase, or my finger's pressure on a trigger, or your eyes moving over the screen to read this post. And so on.
This is why I said above that it was not insignificant that the fall of the vase and the flight of the bullet were determined events. Their significance lies in showing how difficult it is to assign personal, moral responsibility on determinism alone. My volition, or lack of it, and my bumping or firing are significantly like the falling of the vase the motion of the bullet. And this suggests a dilemma: either we regard all concatenated sub-events in some larger event as trivially determined--and thus as void of moral significance in their own right as the falling and flying of a vase and bullet are, respectively, as pure causal alterations in spacetime--or we inexplicably elevate all such (sub)events to a quasi-moral status just so we can bestow the "sum" of their quasi-moral value on the larger event itself, which we hope to treat as a morally culpable action. For let us not forget that a deterministic moral ascription must be taken as a whole. If, ex hypothesi, the laws of nature had altered radically (and very locally) as the vase fell and the bullet flew, such that it never hit the floor (or struck my neighbor), or landed on a suddenly soft floor (or ricocheted off my suddenly adamantine neighbor), or swooped back up to safety (or returned harmlessly into my gun), etc., etc.--if the posterior sub-events in my vase- and gun-scenarios had not obtained with as much deterministic 'completion' as they did, then even despite having possessed a volition to do wrong, I would not be culpable. The vase would be unbroken and my neighbor still alive, so for what could I be blamed? My volition (or lack thereof) would be wholly irrelevant to the ultimate moral status of the macro-event, since its moral value was ultimately "decided" by deterministic sub-events after it. Astoundingly, it seems determinism means that my prior determined volition (or lack thereof) itself only assumes a moral status by virtue of posterior sub-events, which themselves lack a moral dimension. Thus in a twofold way, it is not at all up to me to commit a moral act on determinism, since I not only did not generate that intention myself, but also cannot be assured it will "follow through" to complete a moral (or immoral) action. Amoral or quasi-moral sub-events. Either way, volitions seem the odd man out in a deterministic morality. Why are they alone regarded as truly moral, whereas other equally determined sub-events in conjunction with them are not? I believe this inconsistency arises from an inveterate impulse on our part as agents to stress the peculiar metaphysical--and thus moral--significance of volition as opposed to mere mechanism and chance. The problem, however, is that this seemingly reasonable, and certainly untiring, impulse seems to have no place in determinism.
Hence, if I trust my determinist friend, I shouldn't be too hard on myself for killing my neighbor, since the co-incidence of my determined volition with my determined firing were never really up to me. The coincidence of a homicidal intention with the flexing of my trigger finger is not a moral statement about me; it is a factual description of the causal sequence to which I belong. For a determinist, it seems no more coherent (and no less incoherent) to ascribe moral significance to my volitions or lack of volitions than to ascribe moral weight to the bumping and flexing of my elbows and fingers, respectively.
And so I reiterate my quandary: what 'determines' (if you'll excuse the pun) exactly which 'node' in a deterministic causal sequence bears moral weight? Insofar as my volition to commit a crime is metaphysically inextricable from and incipient in all prior conditions, it seems just as void of moral significance as my bumping the vase. If, however, volition is an intrinsic property of moral fault, this seems to depend on the particular case, which in turn depends on the agent himself--which of course relocates responsibility within the agent himself, in contradistinction to locating "morality" in the 'mere' totality of causal conditions in which (on determinism) he finds himself trapped. If, by contrast, it really is "up to us" to decide where to assign blame, this suggests we at least have a kind of "judicial" freedom in analyzing our own allegedly determined actions.
[It dawned on a couple days later to add to the picture the idea that my responsibility might not even obtain unless it were also coincidentally determined that the judge convicted me of homicide. Failing that, at the end of the whole ordeal, I would not be guilty––despite the facts of my intentions and actions!]