Stony Brook University

logic, metaphysics, arithmetic, geometry, the science of motion, and the
science of right as well; which are not at all founded on experiences and
facts, and serve rather to give reasons for facts and to control them in
advance; which would [also] happen with respect to right, if there were no
law in the world.
The error of those who have made justice dependent on power
comes in part from confounding right and law. Right cannot be unjust, it is
a contradiction; but law can be. For it is power which gives and maintains
law; and if this power lacks wisdom or good will, it can give and maintain
quite evil laws. . . . It is a question, then, of determining the formal reason
of justice and the measure by which we should measure actions to know
whether they are just or not. (R 49-50) 54
The main points here are strikingly similar to those in the Elementa, namely, that the
meanings of right, just and justice and are fixed by their a priori definitions, not by
arbitrary, nominal definitions; that from a priori definitions one can demonstrably
construct “a science of right,” independent of existence, fact, and here, power; that the
definition of right is the a priori ground of civil law; that power maintains civil laws but
does not determine them. Power, in order not to be used arbitrarily, must be restricted by
wisdom and goodness, but more specifically, it must be restricted by the “formal reason”
of justice, which provides the true measure of just and unjust actions.
At this point we expect Leibniz to tell us exactly what this often-mentioned
formal reason (definition, common notion) of justice is. In the passage which
immediately follows the above, Leibniz appears to offer something specific.
After what has been said one can already foresee what this [formal reason]
will be. Justice is nothing else than that which conforms to wisdom and
goodness joined together: the end of goodness is the greatest good, but to
recognize it wisdom is needed, which is nothing else than knowledge of
the good. Goodness is simply the inclination to do good to everyone, and
to [prevent] evil, at least when it is not necessary for a greater good or to
[prevent] a greater evil. Thus wisdom is in the understanding and
goodness in the will. And justice, as a consequence, is in both. Power is a
54 M 47-48: “Il en est de même de la justice. Si c’est un terme fixe qui a quelque signification déterminée,
en un mot, si ce n’est pas un simple son, vide de sens, comme blitiri, ce terme ou ce mot justice aura
quelque définition ou notion intelligible. Et de toute définition on peut tirer des conséquences certaines, en
employant les régles incontestables de la logique. Et c’est justement ce qu’on fait, en fabriquant les
sciences nécessaraires et démonstratives qui ne dépendent point des faits, mais uniquement de la raison,
comme sont la logique, la métaphysique, l’arithmétique, la géométrie, la science des mouvements et aussi
la science de droit, qui ne sont point fondées sur les expériences et faits et servent plutôt à rendre raison des
faits et à les réguler par avance, ce qui aurait lieu à légard du droit, quand il n’y aurait point de loi au
monde.
La faute de ceux qui ont fait dépendre la justice de la puissance, vient en partie de ce qu’ils ont
confondu le droit et la loi. Le droit ne saurait être injuste, c’est une contradiction, mais la loi le peut être.
Car c’est la puissance qui donne et maintient la loi. Et si cette puissance manque de sagesse ou de bonne
volonté, elle peut donner et maintenir de fort méchantes lois. . . . Il s’agit donc de déterminer enfin la raison
formelle de la justice et cette mesure par laquelle nous devons mesurer les actions pour savoir, si elles sont
justes ou non.”
218