Stony Brook University

however ‘public utility’ is defined. With this in mind we can now turn to the following
sections, wherein the subjective sphere of jurisprudence is defined, as having its source in
the moral agent.
The following sections of the Nova Methodus (§§ 14a-19) are extremely
important, since without them, Leibniz’s practical philosophy cannot be properly
understood. They are also the least well-known, and require close scrutiny and additional
context, since Leibniz provides only a sketch of what their main terms mean. After
having defined jurisprudence as the science of just and unjust actions, in view of their
utility, Leibniz now defines the morality of an act in terms of the “moral quality” of a
person.
The morality, however, that is, the Justice or Injustice of the act of the
person, springs from the quality of the person in view of the order of the
action, stemming from preceding actions, and is called moral Quality.
Since, however, the real quality in the order of the action is two-fold,
namely, the power to act, and the necessity to act; therefore, moral power
is called Right, and moral necessity is called Obligation. 40
This is a striking yet puzzling passage, especially since Leibniz does not provide any
immediate explanation for it. In what follows I will try to fill in the relevant contextual
background, focusing on the terms moral quality, right, and obligation. Let us begin by
rephrasing the passage more simply: The morality (or the justice) of the act of a person
originates in the moral quality of the person. The moral quality has a two-fold character:
Right, which is the power to act; and Obligation, which is the necessity to act. Thus the
morality of the act of a person is grounded in the moral qualities of right and obligation,
which are the qualities of a person acting. One of the most important questions here is
wherein lies the “necessity” to act.
Now, let us understand that by comparing jurisprudence with morality (as in §14
and §14a, respectively), Leibniz is not making a distinction between legality and
morality. 41 Rather (like Grotius) he is distinguishing the objective sphere of jurisprudence
from its subjective sphere. In §14, jurisprudence is defined as the science of just and
unjust actions. By “just and unjust actions,” he means actions in relation to an objective
order of things, i.e., those actions that are objectively just, namely, actions that promote
public utility. By contrast, §14a defines a subjective sphere of jurisprudence, i.e.,
morality. The morality of an action is identified not with the just (justum), but with
justice (justitia). This means, among other things, that the morality and justice of an
40 A.6.1.301.§14[a]: “Moralitas autem, seu Justitia, vel Injustitia actionis oritur, ex qualitate personae
agentis in ordine ad actionem, ex actionibus praecedentibus orta, quae dicitur: Qualitas moralis. Ut autem
Qualitas realis in ordine ad actionem duplex est: Potentia agendi, et necessitas agendi; ita potentia moralis
dicitur Jus, necessitas moralis dicitur Obligatio.” In a late revision, Leibniz strikes out “ex actionibus
praecedentibus orta.” Also important is this late revision note: “Potentia et necessitas, id est posse et non
posse non.” This indicates that Leibniz understood potentia also as a moral possibility. This is important
since in the Elementa Juris Naturalis Leibniz clearly associates the just (iustum) with what is possible for a
good person (vir bonus). “Iustum est qvicqvid possibile est fieri à Viro Bono” (A.6.1.480). This will be
discussed at length in Chapter Two.
41 See Schneiders (1966) p. 609.
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