5 Leibniz on Mind, Knowledge, and Ideas. Bibliographical Resources (reminder): Descartes’ Meditations free at: http://www.earlymoderntexts.com/f_descarte.html Leibniz’s Nouveau Essays free at: http://www.earlymoderntexts.com/f_leibniz.html. On/by Chomsky :
Chomsky N. (2000). New Horizons in the Study of Language and Mind. Cambridge UP: Cambridge
McGilvray J. (1999). Chomsky: Language, Mind, and Politics. Polity Press: Cambridge
Materialism is the view that everything that exists is material, or physical.
In short, mental states and processes are either identical to, or realized by, physical states and processes.
This, though, doesn’t entail, for Leibniz, dualism. That is, the existence of both thinking substance and extended substance (vs. Descartes).
He proposes a new view about the relationship between thought and matter.
Leibniz’s viewpoint is that perception and consciousness cannot possibly be explained mechanically (remember that the science of the time was mechanism).
Therefore, perception and consciousness cannot be physical processes.
(In a clock we find parts pushing one another, we don’t find perception, conscious states, thoughts, …)
Everyone must admit that perception, and everything that depend on it, is inexplicable by mechanical principles, by shape and motion, that is, imagine there were a machine which by its structure produced thought, feelings, and perception. We can imagine it as being enlarged while maintaining the same relative proportions … When we went in we would find nothing but pieces which push one against the other, and never anything to account for perception. Therefore we must look for it in the simple substance and not in the composite, or in a machine. (Monadology WF 270)
E.g.: clockwork machinery could never explain time-keeping. Water molecules could never explain liquidity.
There are different levels of explanation which may not reduce one to the other.
He’s not making the fallacious inference:
since we can find no explanation in the machine,
then no explanation could be given.
This is a basic premise of the argument against materialism.
By means of the soul there is a true unity which corresponds to what is called the I in us; This Icould not occur in artificial machines, nor in the simple mass of matter, however organized it may be.
The immortality of the mind follows from its simplicity.
no composition = no destruction;
destruction = decomposition
Monads can only be created or destructed by God.
The morality of human minds depends on them possessing memory and self-consciousness (for this reason they can be rewarded/punished).
There can be no valid inference from a state of subjective uncertainty (Descartes’ doubt) to what is objectively the case.
It is not valid to reason: “I can assume or imagine that no corporeal body exists, but I cannot imagine that I do not exist or do not think. Therefore I am not corporeal, nor is though a modification of the body”. (“Critical Comments of Descartes Principle of Philosophy” 1691: L385)
Remember that Leibniz rejects the Cartesian notion of extended substance on the ground that it lacks unity (extended bodies are aggregates and, as such, lack unity).
The human mind and its body have been programmed by God in such a way that they appear to interact causally with one another.
Leibniz doesn’t endorse this because, properly speaking, human bodies are not substances (they are aggregates lacking unity).
The human body, taken in abstraction from the mind, is never considered by Leibniz to be a substance (cf. Leibniz idealism).
The human body is an aggregate, thus a phenomenon. As such it is not a substance.
So Leibniz may face a problem in understanding the mind-body union.
We would commit the fallacy of composition.
We cannot infer from (i) what is true of the items in a group to (ii) what is true of the group as a whole.
E.g.: It would be like inferring that since Jane loves all the students in a school she loves the school.
These substances are partless, unextended entities, some of which are endowed with thought and consciousness, while others found the phenomenality of the corporeal world (Leibniz’s idealism).
Yet, he also held that mind and body are metaphysically distinct.
For any person P, P's mind is a distinct substance (a soul) from P's body.
Each of our mental states is caused by a prior state of our mind and each state of our body is caused by a prior physical state.
The mind “expresses” its body by perceiving it (perception is a species of expression).
really believe that languages are the best mirror of the human mind, and that a precise analysis of the signification of words would tell us more than anything else about the operations of the understanding (Nouveau Essays, ch.7, sec.6).
He believed that such a language would perfectly mirror the processes of intelligible human reasoning.
Leibniz came close to anticipating artificial intelligence.
Despite its powerful resources for communication, it often makes reasoning obscure since it is an imperfect mirror of intelligible thoughts.
According to this view, cognition is essentially symbolic: it takes place in a system of representations which possesses language-like structure:
all human reasoning uses certain signs or characters. (On the Universal Science: Characteristic; G VII, 204 (S, 17))
This argument is a renewal of the Platonic and Cartesian doctrine.
Like in Plato’s system, innate ideas should solve problems in the philosophy of mathematics. E.g. to explain how a priori knowledge is possible (cf. Socrates majeutics).
This contrasts Descartes’ threefold conception. In particular, the material condition of ideas (i.e. ideas as acts).
To have an idea of a is to have a mental disposition to think of a when the right circumstances occur.
This contrasts with the act of thinking (e.g.: Descartes’ material condition). A disposition is not an act.
Ideas necessarily take possible entities as their objects.
An idea must be about a possible objects.
Thus from the fact that I can think of the round-square it doesn’t follow that I have an idea of it. For a round-square is an impossible object.
This happens according to an entirely internal explanation represented by the complete concept.
But at the phenomenal level, it is no doubt the case that ideas are represented as arriving through one’s senses.
1. Metaphysical level (it includes only monads with their perception and appetition: no causality, no space, no time).
2. Phenomenal or descriptive level (what appears to be happening from the finite, imperfect perspective of the human mind).
3. Object of science (it is an illusion but in which nothing happens that is not based on what really happens in the metaphysical sphere).
God exists if he is possible (God as the object of an idea is a possible object). It is thus a Divine privilege to need only its possibility to actually exist.
Descartes’ argument is vitiated by the assumption that we have an idea of God in Leibniz’s sense, i.e. as a disposition (and that Descartes builds God’s existence into the idea itself).
Pre-established harmony: the human mind with all other substances is causally self-sufficient.
From this + Leibniz’s theory of ideas, we should prove the innateness of all ideas.
This is reminiscent of Descartes reply to a certain Broadsheet: nothing reaches our mind from external objects …
Does this prove that ideas are innate?
(i) Ideas are disposition and
(ii) Dispositions are mental states.
Thus: (iii) since mental states cannot be externally caused, no idea is externally caused.
1. This only proves that an idea is not sensory- dependent in its origins: it could be formed with the formation of the mind (it rests on what we mean by “innate”).
This critique is a good one. The first can be answered.
The notion of reflection can be clarified in such a way that what happens in post-natal acts of reflection is that the mind first come to conscious awareness of an idea that has always been there.
See Socrates’ maieutic (the philosopher like a midwife).
Leibniz doesn’t accept, though, Plato’s theory of reminiscence, i.e. that we remember ideas/forms from a previous life.
Claims of universal necessary knowledge cannot be justified by appealing to sensory evidence.
Senses can give only instances of truth. They cannot guarantee that what happens will always happen. Senses are linked to actuality …
Descartes can answer in appealing to God’s benevolence: God is not a deceiver.
Leibniz cannot answer this way since he dismisses Descartes’ appeal to God in order to solve epistemological problems.
Our mind is a mirror of God.
Our innate beliefs have the same structure as the eternal truths in the Divine mind.
Unlike Descartes who appeals to God’s benevolence, Leibniz appeals to the isomorphism between our min and God’s mind (monads are the mirror of God).
It is not clear what the nativists are defending. Either:
(i) the view that the existence of actual knowledge and concept-possession is innate or
(ii) that the mind is born with the potential to acquire such knowledge and concepts.
New-born babies show no sign of actual knowledge of necessary truths; they don’t know the truths of logic and mathematics.
All knowledge and concepts that one ever comes to entertain would be innate.
Ideas as dispositions/potentials/inclinations/… are something less than actual knowledge. Yet, this amount to assert something more that the mere claim that the child has bare potential to understand logic etc.
It is differentially predisposed toward employing certain principles and thinking in some ways rather than others.
I have also used the analogy of a veined block of marble, as opposed to an entirely homogeneous block of marble, or to a blank table, what the philosophers call a tabula rasa. For if the soul were like such a blank tablet, then the truths would be in us in the same way as the shape of Hercules is in a piece of marble when the marble is entirely neutral as to whether it assumes this shape or some other. However, if there were veins in the block which marked out the shape of Hercules rather than other shapes, then the block would be more determined to that shape, and Hercules would be innate in it, in a way, even though labor would be required to expose the veins, and to polish them into clarity, removing everything that prevents their being seen. (Leibniz NE, Preface, 52)
We are innately programmed to shape the world in terms of things rather than cluster of features or properties. E.g. it comes more natural to us to respond to cats rather than instances of furriness. (vs. Quine’s “gavagai” example).
The appeal to disposition is explanatory empty.
It falls under the very same criticism Descartes addresses to the Scholastic notion of dormitive powers. It is a circular explanation.
fragility = the disposition to break given some circumstances …
we explain the glass breaking on the hard floor by its fragility.
The same with a thought.
If having the idea of a triangle is a disposition to have it in such circumstances/stimulus, then one has an idea of a triangle when facing such circumstances/stimulus.
Both physical and mental dispositions are grounded in non dispositional micro-structural properties of the physical/mental.
In the case of the mind the micro-structure at work are the minute perceptions. They are minute in virtue of their intensive, not extensive, magnitude. They are too low in intensity to become conscious.