Stony Brook University

follows where we left off on page 89 just above: “So we observe that [the principle]
teaches truths so evident that robbers, pirates, and bandits are compelled to observe [the
truths] among themselves” (NE 1.2.1.89). 27 This implies that from the principle of joy
and sorrow one can derive powerful and evident moral truths. However, if this is
Leibniz’s idea of how a demonstrable moral science is to be carried out, it would fail
immediately, since what is suggested here could easily be understood this way: The
maxim pursue joy and avoid sorrow is so obviously true that even immoral persons will
deduce that they may use it to serve their own advantage at the expense of everyone else.
And, if they refrain from harming each other and avoid getting harmed by others, they
can achieve their immoral aims quite suitably to themselves.
So far, the discussion of practical instincts and sensations has raised a lot of
questions but has not provided many clear or satisfying answers. We have established
with certainty only that is a fact that we have sensations of pleasure and pain and these
have something to do with morals. However, the dialogue now turns to a discussion of
practical principles based on reason and which involve rules of justice. Part of the reason
for this turn is the direction of Locke’s own line of argument. Locke is shown to say that
thieves do in fact follow certain “rules” and “maxims” of justice; but this does not prove
that they are following innate principles. It shows only that they maintain “rules of
convenience” among themselves in order to “preserve their confederacy.” Leibniz’s
response is brief, but highly significant:
Very good; if you were speaking generally of all mankind, you could not
improve on that. This is how these laws are engraved in the soul, to know
the consequences of our preservation and of our true goods]. (NE
1.2.2.89) 28
Basically, Leibniz is saying that Locke’s point shows only one thing: that these maxims
(or laws) of justice are not to be restricted to a sub-community of strictly self-interested
agents, but rather are to be the laws of a universal community. This view is generally
characteristic of Leibniz’s definitions of the just, which, as we have seen, has been
defined in terms of public utility, or the common good, or the conservation and perfection
of society. More appropriately, this view stems from his earlier definitions of justice and
convenience. For Leibniz the term ‘convenience,’ which Locke uses here, is not to be
passed over; it refers specifically to the universal fittingness of justice, that is, to the
fittingness between what is one’s own and what is everyone’s own. 29 These rules and
maxims are indicate to us that the requirements of survival and our true good never
exclude another’s good and we must endeavor as possible to promote everyone’s good.
Leibniz may also have in mind the “universal justice” or virtue that is characteristic of the
third degree of right—although, in this immediate context he does not speak of justice as
27
A.6.6.89: “Aussi voyons nous qu’elle enseigne des verités si evidentes, que les larrons, les priates et les
bandits sont forcés de les observer entre eux.”
28
A.6.6.89: “Fort bien, on ne sauroit rien dire de mieux à l’egard de tous les hommes en general. Et c’est
ainsi que ces loix sont gravées dans l’ame, savoir comme des consequences de nostre conservation et de
nos vrais biens.”
29
As cited in my Chapter Four, from “De Justitia Et Novo Codice Legum Condendo” (1679-80):
“JUSTITIA est constans voluntas suum cuique tribuendi. SUUM scilicet, id est quod penes unumquemque
esse convenit. . . . CONVENIRE autem rebus illud videtur quod in summa optimum est” (A.6.4.2833).
177