Routledge History of Philosophy Volume IV

378 LEIBNIZ: TRUTH, KNOWLEDGE AND METAPHYSICS
innate ideas are innate mental dispositions; they are dispositions which we have
had at least since birth. This is the form of the doctrine which Leibniz has
primarily in mind when he defends the innateness of mathematical and
metaphysical concepts against Locke. In his polemic Locke had adopted a twopronged
strategy of attack on innate ideas. According to Locke, the thesis of innate
ideas is either empirically false—it ascribes highly abstract concepts to infants —
or it is condemned to triviality. 100 In reply Leibniz seeks to show that his own
dispositional theory of innate ideas constitutes a third option which is not caught
in the mesh of Locke’s polemic. To claim that the mind has an innate idea of x is
not just to say, as Locke supposes, that it is capable of thinking of x; a distinction
must be drawn between dispositions and ‘bare faculties’. 101 That Leibniz is right
to draw such a distinction can be shown by reference to the case of a physical
disposition such as fragility. When we call an object fragile, we are not just
saying that it is capable of breaking; otherwise any object which breaks is
fragile. Leibniz’s theory of innate ideas thus implies at least that the mind is
differentially predisposed to form certain thoughts rather than others. Here Leibniz
seems to be reviving Descartes’s thesis that ideas are innate
in the same sense as that in which we say that generosity is ‘innate’ in
certain families, or that certain diseases such as gout or stones are innate in
others; it is not so much that the babies of such families suffer from these
diseases in their mother’s womb, but simply that they are born with a
certain ‘faculty’ or tendency to contract them. 102
In one way, however, Leibniz’s dispositional theory of innate ideas seems to
differ from Descartes’s. Unlike Descartes, Leibniz seems to hold that mental
dispositions cannot be basic properties; they need to be grounded in fully actual,
non-dispositional properties of the mind. Here Leibniz may be responding to
Malebranche’s criticism that the Cartesians inconsistently countenanced basic
powers in psychology, while rightly banishing them from physics. 103 But while it
is obvious how, say, fragility can be grounded in structural properties of the
glass, it is less clear what could serve to ground mental dispositions. In order to
meet this requirement, it seems that Leibniz once again appeals to his doctrine of
unconscious perceptions. My innate disposition to think of a triangle, for
example, would be grounded in an unconscious perception which has triangle
content. It is this doctrine which Leibniz appears to have in mind when he writes
in the New Essays that ‘ideas and truths are innate in us—as inclinations,
dispositions, tendencies, or natural virtualities, and not as actions; although these
virtualities are always accompanied by certain actions, often insensible ones,
which correspond to them.’ 104
The dispositional theory is Leibniz’s main theory of innate ideas, but it is not
the only one. Leibniz also advances what we may call the ‘reflection account’.
According to this account, the idea of substance, for example, is innate in the sense
that we can acquire it by turning our mental gaze inward and reflecting on the