Psychological Determinism in Leibniz

Leibniz, Classical Theism, and the Problem of Evil - Chapter 4 (2 of 4)

Greetings, subscribers. As followers of Theological Letters know, I’m feverishly working to finish my forthcoming book on Leibniz and the problem of evil, and I have promised to post fresh installments of my progress every Sunday.

To date, I have posted the Introduction, Chapter 1, Chapter 2, Chapter 3, and part 1 of Chapter 4. Today, I post the second installment of Chapter 4, Psychological Determinism in Leibniz.

If you have yet to read all that comes before, I recommend you do so for context. Links to all prior sections are below. Be watching for the second installment of Chapter 4 next Sunday. Enjoy!

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Psychological Determinism in Leibniz

Recall from chapter 1 that Leibniz believes everything has a sufficient reason for being so rather than otherwise. Nothing escapes the watchful gaze of PSR, and this includes psychological events and free choices. Hence, whatever one thinks about free will, he must still account for why an agent (free or not) chooses as he does. No choice is without reason. This is not to say, of course, that every choice is reasonable — certainly not.¹ But when someone chooses p over not-p, there must be a reason he has done so. In a word, even a “free choice” must satisfy PSR. 

Recall that this is precisely Leibniz’s complaint with the voluntarism of Clarke and Newton’s God. Leibniz does not simply resolve his search for a sufficient reason by tracing the contingent truths of our world to the necessary truth, God exists. Rather, we must account for why God produces our world, and optimism provides an answer. By rejecting optimism, however, the Newtonians make God’s choice to create our world capricious and arbitrary in the truest sense — an act of arbitrium, or bare “choice” without (sufficient) reason.² It is not enough to say one has freely chosen to do something. PSR demands a reason why he has chosen thusly. 

Such a stance echoes the standard compatibilist line that no event is causeless, and that includes psychological events.³ Leibniz agrees. Little imagination is required to see how such a view naturally tumbles into psychological determinism. Any number of authors have made the point, but we’ll use Bertrand Russell as our guide. 

In his Critical Exposition of the Philosophy of Leibniz, Russell articulates well the problem of psychological determinism that arises when PSR is applied to choice.⁴ Russell begins by highlighting the very point made above, namely that, for Leibniz, every event has a cause and psychological events are no exception. But Russell adds to this Leibniz’s affirmation of the law of excluded middle — that is, the principle of logic that a proposition is either true or false, there is no middle. When applied to future contingents, as Leibniz does, not only are psychological events caused, but their causes must be predetermined. For if it is true that tomorrow Raleigh will choose r instead of not-r, then there is a sufficient reason for this truth, which evidently precedes the act of choosing.⁵ 

For this reason, Russell believes Leibniz should have cast off the notion of contingency altogether. Yet, Russell recognizes that Leibniz was committed to developing a system that could cohere with Christian dogma, and thus abandoning freedom for absolute necessity was a non-option. For Christianity has always affirmed free will. As Russell puts it, 

The whole doctrine of contingency might have been dropped with advantage. But that would have led to a Spinozistic necessity, and have contradicted Christian dogma. Accordingly he [Leibniz] held ... that all existential propositions and all causal connections are contingent, and that consequently, though volitions have invariable causes, they do not follow necessarily from those causes.⁶ 

Russell here alludes to one of the ways in which Leibniz sought to evade the slippery slope toward necessity. The philosopher of Leipzig often insists that the various influences upon our will are only inclining influences, never necessitating or determining influences (e.g., G 6:115-7). The point was intended to preserve free choice.⁷ Yet, few interpreters find the distinction helpful in breaking the chain of necessity. Leroy E. Loemker, for example, writes:

For nearly forty years, Leibniz showed his uneasiness about this conception of freedom and made efforts to explain or modify it, but never in any way which threatened the great chain of essentialistic determinism or admitted a degree of indeterminism. The distinction between inclinatio and determinatio, and between metaphysical and moral determinism did not help.⁸ 

Why did the distinction not help? According to Loemker, the distinction fails because Leibniz denies that the will is ever in a state of equilibrium. Without equilibrium, any inclining influence is a determining influence, just as any imbalance in a balance scale suffices to tip it.

Such a mechanical analogy may seem unfair. After all, rational agents are not mere machines. Even if we feel a pull in a certain direction, we can resist or choose a different course of action. The problem, however, is that the analogy is Leibniz’s own! When seeking to prove the chimerical nature of equipoise — that is, the idea that the will is indifferent to the choices before it — he Leibniz employs Archimedes’ definition of equilibrium as equal weights at equal distances from a common center (e.g., C 518-23).⁹ And his point is that were the will in such a state, no choice could follow. Instead, choice is always an expression of one’s dominant inclination. Or to use Leibniz’s own words, “There is always a prevailing reason which prompts the will to its choice” (G 6.127/H 148). Granting the point, inclining influences are determining influences, for these are what tip the scale, as it were, in favor of whatever choice one makes. 

A second way in which Leibniz tries to protect contingency is by denying that there is any necessary connection between the subject and the acts predicated of the subject. We saw this when looking at Leibniz’s theory of truth. Recall that Leibniz holds that necessary truths, such as the geometric truth, “All squares have four sides,” are reducible to identity, thereby demonstrating their necessity. As for contingent truths, yes, Leibniz grants that the predicate, “crossing the Rubicon,” is in Caesar, but this historical truth cannot be reduced to identity, and therefore, it can be negated without contradiction. Such is the reason this truth is contingent. 

Nicholas Rescher is quick to point out, however, that Leibniz’s rejection of necessity in this case is only a rejection of logical or semantic necessity. Yes, our analysis of historical truths — including truths about “free” choices — never resolve into an identity claim. Fair enough. And yes, this lack of an identity claim means that we can utter the phrase, “Caesar did not cross the Rubicon,” without uttering a formal contradiction. But, given PSR, Leibniz cannot possibly mean that a given event might not have followed from its (sufficient) reasons. This event has causes, and those causes must be, by Leibniz’s own reasoning, sufficient to bring about the event.¹⁰ 

Russell makes the very same point and finds nothing in Leibniz that is able to break the chain of necessity between cause and psychological event. Like Loemker, Russell harps on Leibniz’s rejection of indifference in the will as the crux of the problem. He writes, “[Leibniz] rejected entirely the liberty of indifference ... and even held this to be self-contradictory. For it is necessary that every event should have a cause, though it is contingent that the cause should produce its effect. He held also that the indifference of equilibrium would destroy moral good and evil.”¹¹ Why did he reject the concept? As we have seen, PSR forces Leibniz down this road. For if a psychological event were to spring from the bedrock of indifference, it would be an event without a cause for being so rather than otherwise, which is impossible, according to PSR — a principle to which Leibniz is unwaveringly committed. 

From what, then, do psychological and physical events spring? Russell points to Leibniz’s notion of spontaneity, and here we reach yet another means by which Leibniz seeks to evade necessity. We already encountered the concept of spontaneity in our discussions of the monadology. Recall that unlike mechanical systems in which the movement of a thing is determined by external motion, collision, and transferred force, monads move from one perception to the next by an internal power. Such change “takes place in substance spontaneously and from its own depths” (NE II, xxi, 72, RB 218-9). Now, Russell highlights the key point as it relates to necessity: “Spontaneity ... is contingency without constraint, and a thing is constrained when its principle comes from without.”¹² This line of defense is common amongst compatibilists — a defense I highlighted above in reference to our hypothetical Jane. Compatibilists often claim that what makes a choice free or not is whether it arises from within or is coerced from without. In the absence of coercion, an act is free, for the agent did as he pleased. Leibniz often makes the point that monads, being windowless (E 705), are entirely free from external coercion or constraint (e.g., G 6:135). 

Yet, this fact hardly suffices to rescue monads from necessity. As Russell points out in the very next sentence, “By the principle of a thing, I imagine Leibniz must mean the sufficient reason of its changes.”¹³ Where is the sufficient reason for how a thing changes if not from without? Quite simply, the internal principle of spontaneous change is the idiosyncratic nature of the subject.¹⁴ And where does this nature, which determines every change, come from? To quote Leibniz, “God … gives to each substance in the beginning a nature or internal force that enables it to produce in regular order … everything that is to happen to it” (L 457). With such an assertion, we stand at the precipice of determinism, as per the consequence argument of the libertarian: If my choices are determined by prior causes and those prior causes are traceable to causes prior to the exercise of my will, then I have no control over my choices.¹⁵ If a subject’s nature is the sufficient cause of all the subject’s spontaneous changes — including “free” choices — and if this determining nature is had by the subject prior to and without the subject’s choosing, then the subject’s spontaneity does not express self-determination. Rather, the being’s choices reflect God’s predetermination of the subject. For the subject’s spontaneous “choice” expresses the nature God gave to it at its beginning. 

Now, before concluding that Leibniz has fallen off the precipice of necessitarianism, Russell acknowledges that Leibniz draws a distinction between freedom and bare spontaneity. In other words, all monads have spontaneity, but not all monads are free. So what differentiates free spontaneity from bare spontaneity? Leibniz answers that freedom is spontaneity combined with reason. And while spontaneity may be found in beasts and all bare monads, reason is not.¹⁶ Very well, but does adding reason to the mix alleviate the consequence argument? Russell doesn’t think so. 

He points out that, for Leibniz, adding reason to spontaneity means that rational volition is always determined by one’s knowledge (or perception) of the good — since the good is the object of rational deliberation.¹⁷ Rather than breaking the chain of necessity, it replaces it with a new inevitability. For Leibniz, volition is necessarily determined by desire, “and if the good means what is desired,” Russell argues, “then volition would be necessarily determined by the good.”¹⁸ 

We see the point quite clearly in Leibniz’s theology. God’s volition is determined by his knowledge of the best. Why? Because the object of both intellect and will is the good, so an omniscient being cannot fail to know the optimal good, and the will cannot fail to choose the optimal good. Such is the necessary consequence of coupling omnibenevolence and omniscience, which is the very cornerstone of Leibniz’s optimism.¹⁹ In the case of creatures, the will operates amidst finitude and ignorance, so choice is determined not by the good per se but by the perceived good. But the point hardly rescues freedom. For the connection between judgment and action is no less necessary than in God. Our volition is no less determined by the good than God’s own. The sole difference is that God’s judgments are infallible while ours are fallible. As Russell puts it, “had [Leibniz] been consistent, he would have said boldly, all sin is due wholly to ignorance.”²⁰ In other words, were we to perceive the good rightly, as God does, it would determine our volition just as it determines God’s own. Whatever choices we make contrary to the good are not owed to a power of contrary choice or chimerical indifference. The unpredictability of our choice is due solely to ignorance.