Stony Brook University

terminology, Leibniz holds that natural right and justice cannot be based on what is
purely possible to do, but must be based on what is right and morally necessary to do.
Therefore (to answer the Euthyphro problem) “goodness and justice have their grounds
independent of will and of force” (RM 46). 51
In the Monita we got a fairly clear idea of the source of these grounds,
independent of will and force; namely, the ideas of right in the divine understanding. In
the Meditation, Leibniz solves the problem of voluntarism in a similar way, by
developing several distinct notions of right and justice. He begins by calling for a “formal
reason” (raison formelle) of justice. This formal reason cannot be power, since, in
addition to the reasons so far given, “if power were the formal reason of justice, all
powerful persons would be just, each in proportion to his power; which is contrary to
experience” (RM 48). What is needed is a formal reason or common notion of justice that
is universally valid for God and humans alike.
It is thus a question of finding this formal reason, that is to say, the why of this
attribute, or this [notion] which should teach us what justice is, and what men
mean in calling an action just or unjust. And this formal reason must be common
to God and to man; otherwise one would be wrong in wanting to attribute, without
equivocation, the same attribute to both: these are fundamental rules of reasoning
and of discourse. (RM 48) 52
Part of Leibniz’s motivation in this passage is to refute certain “dogmas” which deny the
universality of the concept of justice. 53 This formal reason will make the use of power
legitimate and the application of justice consistent. Thus, we must distinguish between
the “necessary and eternal truths which must be the same everywhere” from “that which
is contingent, changeable or arbitrary” (RM 49). To do this, Leibniz devotes perhaps an
inordinate amount of space (including graphics) to show how mathematical patterns, no
matter how complex, remain consistent, certain, and universally agreeable; and, no one
thinks that these patterns hold for God but not for humans (or vice versa). Thus:
The same is true of justice. If it is a fixed term which has some determined
meaning; if, in a word, it is not a simple sound, without sense, like blitiri;
this term, or this word, justice, will have some definition or some
intelligible notion: and from every definition one can draw certain
consequences, by using the incontestable rules of logic; and this is
precisely what one does in building the necessary and demonstrative
sciences which depend not at all on facts, but solely on reason, such as
51 M 42: “… la bonté et la justice ont leurs raisons indépendentes de la volonté et de la force.” In section 4,
we will return to Leibniz’s criticism of Hobbes in relation to the first degree of right (jus strictum).
52 M 45: “Il s’agit donc de trouver cette raison formelle, c’est-à-dire le pourquoi de cet attribut, ou cette
notion qui nous doit apprendre en quoi consiste la justice et ce que les hommes entendent, en appelant une
action juste et injuste. Et il faut que cette raison formelle soit commune à Dieu et à l’homme. Autrement on
aurait tort de vouloir attribuer sans équivoque le même attribut à l’un et à l’autre. Ce sont là les reegles
fondamentales du raisonnement et du discours.”
53 In the Theodicy (sec. 173-177) Leibniz argues against the dogmas that “(1) the nature of justice is
arbitrary, (2) that it is fixed, but it is not certain God will observe it, (3) that the justice we know is not the
justice he observes.” But these are refuted if justice has a “common notion.”
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