Stony Brook University

motivating principles do not tell us what justice is, nor do they provide the normative
justifications and criteria for justice itself. 34 Normative justification depends, as we have
seen, on the definitions of right, just, and justice. Third, the strength and universality of
Leibniz’s demonstration depends on whether one accepts the assumptions of God and
immortality. Yet it is not difficult to reject these assumptions, and many do. Therefore, it
would appear risky to rely on them, and more reasonable to seek assumptions based on
reason that are actually more apt to be universal. Furthermore, if these assumptions were
rejected, would the maxims of justice suddenly lose their truth? Would we indeed
become a community of thieves, so to speak? Leibniz says yes, and this is a position he
will maintain. But they would not lose their meaning and content, and this is a position
Leibniz will also maintain. Thus, if the assumptions were rejected the maxims of justice
would lose only some powerful motivations.
So far Leibniz has offered at least two ways to establish moral doctrine as a
demonstrative science: (1) by means of principles of feeling or instinct, such as the
principles of pleasure and pain; (2) by means of reason, such as by deduction from the
assumptions of God and immortality. We may assume Leibniz has in mind that the
maxims, rules, and definitions related to justice itself are also demonstrable, although he
has not explained how. We also must be careful about making the distinctions too strict.
As we saw, for example, even the demonstration based on theological assumptions
involves finding pleasure in serving God. We will continue to work out these issues as
we proceed.
At this point the dialogue with Locke begins to wade through a lengthy and
complex discussion of a variety of instincts, inclinations, passions, precepts, laws, and
practical and speculative truths. To sort out these matters, the dialogue must be broken
down into several arguments. The overall result of these arguments will be a clearer
indication of how principles of instinct and reason are distinct, related, and in what sense
they are considered demonstrable. The first argument deals with the relationship between
pleasure and higher-level happiness, a relationship in which “reason” plays a role. As we
saw in section 2, Locke admits only one innate practical principle, that is, the desire of
happiness and aversion to misery; or, as he also puts it, “inclinations of the appetite to
good” (E 1.2.3). He does not admit, however, that this principle involves any innate
proposition. Leibniz now seizes on Locke’s first admission, but makes an important
modification.
I am delighted, sir, to find that you do after all acknowledge innate truths,
as I will shortly maintain. This principle agrees well enough with the one
which I have just pointed out, which leads us to pursue joy and avoid
sorrow. For happiness is nothing but lasting joy. However, what we
incline to is not strictly speaking happiness, but rather joy, i.e. something
in the present; it is reason which leads us to the future and to what lasts.
(NE 1.2.3.90) 35
34 I think that Leibniz’s argument here does not represent his considered position on the highest good,
which is virtue (or so I argue in Chapter Six), and virtue can be executed perfectly well—not without great
difficulty, but—without expectation of reward, happiness, or fear of punishment.
35 A.6.6.90: “Je suis ravi, Monsieur, de vous voir reconnoistre en effect des Verités innées, comme je diray
tantost. Ce principe convient assés avec celuy que je viens de marquer, qui nous porte à suivre la joye et à
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