Stony Brook University

Leibniz also says that what is true for speculative principles is also true for
practical principles: “As I have already pointed out; the finest moral precepts and the best
prudential rules in the world have weight only in a soul which is as sensitive to them as to
what opposes them” (NE 2.21.35). This means, as he explains, that when we prefer
something less good than what the intellect tells us is a higher-degree good, it is because
the ideas in the intellect lacks sufficient sensitivity to be noticed and effective. Thus, to
insure that we follow the truly good requires that we to train ourselves to maintain images
pertaining to the good. 90 And this begins to get us to the third point. Since both abstract
thought and practical principles require imagination, and imagination is a function of our
sensibility, then the intelligible truths of morality require “fleshing out,” so to speak. That
is to say, practical principles must become sensitized by being practiced.
Despite the obscuring effect of sensual inclinations and the motivational weakness
of rational principles, Leibniz does not tell us to eliminate inclinations and passions, but
rather to make intelligible ideas more sensual and thus to make them the principles of
action. In response to Locke, who had concluded that innate principles do not exist
because we continually act against what we know to be right, Leibniz replies that we tend
to turn our thoughts aside from the good because “the future and reasoning seldom strike
as forcefully as do the present and the senses” (NE 1.2.11). This implies that certain
acquired inclinations may be misguided, but also implies that the motives of reason are
too weak to overcome those inclinations. Thus, for a practical principle to be an effective
motive, it must have sensual content. Conversely, the more distinctly a sensation is
perceived in the mind, the more effectively the mind can sort out its particular causes,
effects, and meaning. And this brings us to the third point, to see how Leibniz thought
that virtues could be developed to incorporate the principles of instinct and reason.
As we have seen, Leibniz indicates that both instinct and reason are insufficient
moral motives. But an important element of his practical philosophy is the role he assigns
to virtue as a remedy for these insufficiencies. One example is especially relevant, since it
occurs during the discussion of innate practical principles. Locke criticizes the idea of
virtue, since ultimately it can tell us nothing definitive or useful. He argues that if innate
principles exist, then we should be able to produce a catalog of them. Such a catalog,
Locke notes, had been attempted by Lord Herbert, who includes Virtutem cum pietate
conjunctam optimam esse rationem cultûs divini among his list of innate principles (E
1.2.15). 91 Locke then argues that the meaning of ‘virtue’ is ambiguous between (a) what
some community considers praiseworthy, and (b) an action conformable to God’s will. If
‘virtue’ means (a), then virtue will be so variable that it cannot be said to be innate, and if
(b), virtue will “amount to no more than that God is pleased with the doing of what he
commands”; and while this may be true, it does not tell us “what it is that God doth
command” (E 1.2.18). Therefore, Herbert’s principle of virtue is useless. Leibniz
responds, characteristically, by asserting that while the word ‘virtue’ may be relative in
its application, its general notion is universally agreed upon. He points out that the
Aristotelian definition of virtue is “a general disposition to moderate the passions by
means of reason, or more simply still a disposition to act in accordance with reason” (NE
1.2.19). Under this definition, virtue does not form part of the meaning of a moral
90 Leibniz speaks of these things in Book 2, Chapter 21, “On Power and Freedom.”
91 “Virtue joined with piety is the best worship” (NE 1.2.15). Pehaps more accurate would be: “Virtue
joined with piety is the best account of worship of the divine.”
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