Stony Brook University

of rational beings to do what is, in the end, conducive to such a society. But it is the
definition of right as the moral quality of rational substances that determines the
requirements of the whole science. Thus Right (and its necessary correlate, obligation) is
an essential “element” of the science. It is, however, only one-half of the science. In
accord with his method, having begun with definitions, Leibniz must now outline the
precepts that derive from them, precepts he uniquely borrows from a much older
tradition, namely, Roman law.
Section 4: The derivation of precepts: the three degrees of natural right
After having treated the definitions of right, Leibniz now turns to the other
elements of this science of jurisprudence, namely, its precepts. Just as geometry has
general laws or rules following from definitions, the science of right has prescriptive laws
specifying what is commanded, permitted, or forbidden. First, Leibniz considers the
matter of a precept, and then the form. The matter is “what is expressly emphasized in the
Laws, in which the status or Right is made secure and as uncontroversial as possible.” 81
Form refers only to the arrangement of the laws by chapters and subchapters, following
the definitions. But his main objective is “so far as possible, to abstract a universal
precept from the definitions.” 82 This will be his task in the sections that follow.
Before getting to the precepts, there are a few clarificational remarks. Leibniz
repeats the methodological need for “a compass to guide us through the immense sea of
jurisprudence” and for the “decision principles” to guide the jurisconsult. 83 He speaks
here of two points of view that the jurisconsult must maintain: one is the rational measure
from natural right, and the other is the measure of civil law, or questions of fact. For
example, if a custom is to become a matter of positive law, one must take into account
both the consistency of the custom with present facts of the matter and with other laws.
But primarily, the custom must not violate the natural law. Thus the jurisconsult’s
guiding principle consists of a dual science: Scientia Nomothetica and Scientia Juris
Naturalis (p. 342.§70).
As for the guiding compass, it seems that Leibniz has already provided one by
defining the terms of right. But now he has in mind to show that while various historical
opinions on natural right (or natural law) have some truth to them, they all may be
reconciled by his own. 84 The first historical figure that Leibniz cites is Plato, as having
established that the foundation of right (or law) is public utility. Although as
Thrasymachus had countered (in Plato’s Republic Bk. 1, 338c), the just is what is useful
to the stronger. 85 We have already seen how Leibniz thinks Plato’s and Thrasymachus’
positions are reconcilable, namely, through the claim that God’s power lies in his
wisdom, and his interest lies in public utility. We will come back to this point in §75.
Leibniz also cites Aristotle and the Stoics as having held that the natural law consisted in
81
A.6.1.307.§23: “Inserantur ea tantum, quae in Legibus expresse extant, et certi minimeque controversi
Juris sunt.”
82
A.6.1.309.§24: “Deinde observetur inprimis, ut, quantum fieri potest, abstrahantur universalia.”
83
A.6.1.341.§§ 69 & 70.
84
A.6.1.342.§71: “Juris Naturalis non minutissima quaeque, sed principia tantum persequemur. Eaque
primum ex sententia aliorum, deinde et nostra.”
85
A.6.1.342.§71: “Plato passim Juris fundamentum statuit, to koine sumferon, publicum utilitatem. In
libris de Republica Thrasymachus disputat Justum esse: Potentiori utile.”
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