5 Leibniz on Mind, Knowledge, and Ideas

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5Leibniz on Mind, Knowledge, and Ideas
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• Bibliographical Resources (reminder)
• Descartes Meditations free at
• http//www.earlymoderntexts.com/f_descarte.html
• Leibnizs Nouveau Essays free at
• http//www.earlymoderntexts.com/f_leibniz.html

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• 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

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Critique of Locke

• The New Essays on Human Understanding is an
  explicit critique of Locke who fails to recognize
  that the principle of necessary truths are latent
  in our mind.
• Locke matter may think.
• The main purpose of the Essays is to vindicate
  the immateriality of the human soul/mind.

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• Leibnizs anti-materialism
• 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.

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• The realms of the mental and the physical, for
  Leibniz, form two distinct realms.
• This, though, doesnt entail, for Leibniz,
  dualism. That is, the existence of both thinking
  substance and extended substance (vs. Descartes).
  
• Leibniz opposes both materialism and dualism.
• He proposes a new view about the relationship
  between thought and matter.

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• If the human mind were identical to the brain it
  would be difficult, if not impossible, to
  maintain that it is a mirror of God (remember
  monades are mirrors of God).
• The immateriality of the soul/mind also offers a
  good foundation for the Christian doctrine of the
  immateriality of the soul and thus of personal
  immortality. The body decomposes, while the soul
  survives.
• We should remember that back in Descartes and
  Leibnizs time science wasnt secular.

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• Most of Leibniz's arguments against materialism
  are directly aimed at the thesis that perception
  and consciousness can be given mechanical (i.e.
  physical) explanation.
• Leibnizs 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.

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• Perception and what depends upon it is
  inexplicable on mechanical principles, that is,
  by figures and motions.
• (In a clock we find parts pushing one another,
  we dont find perception, conscious states,
  thoughts, )
• Therefore it is in the simple substance (monade),
  and not in the composite or in the machine, that
  one must look for perception.

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The Mill Argument

• Goal to prove the immateriality of the soul.
• 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)

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• The mill argument can be dismiss on the ground
  that it overlooks the fact that we may lack the
  understanding or knowledge to see consciousness
  present in the machine. Were incapable of coming
  out with Look, a thought over there. Yet,
  there may be a thought
• The argument is best understood in focusing on
  the notion of explanation, i.e. there is
  something about mental life that mechanism cannot
  explain.

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The limits of a mechanistic explanation

• The unity of consciousness cannot be explained
  invoking mechanistic principles (our mental life
  is not compartmentalized).
• 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.

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• Leibniz is not offering an argument from
  ignorance.
• Hes not making the fallacious inference
• since we can find no explanation in the machine,
  
• then no explanation could be given.

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• The machinery could never, in principle, explain
  the unity of consciousness.
• This is a basic premise of the argument against
  materialism.
• The direct experience of ourselves is the only
  direct experience we have of substantial unity.
• By means of the soul there is a true unity which
  corresponds to what is called the I in us This I
  could not occur in artificial machines, nor in
  the simple mass of matter, however organized it
  may be.

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• The human mind being a simple and immaterial
  substance is also naturally immortal.
• The immortality of the mind follows from its
  simplicity.
• no composition no destruction
• destruction decomposition
• Monads can only be created or destructed by God.

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• True immortality (the personal immortality
  relevant for ethics) involves also memory and
  self-consciousness (apperception). Only spirits
  have this property.
• The morality of human minds depends on them
  possessing memory and self-consciousness (for
  this reason they can be rewarded/punished).
• Importance of memory for personal identity.

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Critique of Descartes

• The cogito argument is a sophism.
• 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)

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The Mind-Body Problem

• Leibniz's rejection of materialist conceptions of
  the mind was coupled with a strong opposition to
  dualistic views concerning the relationship
  between mind and body.
• Leibniz criticizes Descartes system because it
  doesnt explain how the soul can influence the
  body how the mind unites with the body.

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• Leibniz's opposition to Cartesian dualism stems
  not from a rejection of unextended substances,
  but from his denial of the existence of genuine
  extended material substances.
• To begin with, Leibniz held the Scholastic thesis
  that being and one are equivalent (the unity
  of substances).
• 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).

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• Pre-established harmony
• The human mind and its body have been programmed
  by God in such a way that they appear to interact
  causally with one another.
• There is a constant conjunction. This lead
  philosophers to falsely believe that there is
  actual causality.
• This is the denial of the mind/body interaction.

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• The Cartesian mind-body problem rests on the
  assumption that both the mind and the body are
  substances.
• Leibniz doesnt 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.

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• In his later philosophy Leibniz holds that the
  human body is grounded in immaterial souls or
  monads, but it is not itself immaterial.
• So Leibniz may face a problem in understanding
  the mind-body union.

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• The doctrine of pre-established harmony has been
  introduced as a thesis concerning the interaction
  between substances (i.e. the windowless monads).
• Thus if pre-established harmony is used to solve
  the mind-body union, the body should be, contrary
  to what Leibniz says, a substance.

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• Given that pre-established harmony holds among
  substances, we cannot validly infer that the mind
  is in harmony with the body, for the latter is
  not a substance.
• 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.

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• The doctrine of the pre-established harmony could
  be used within Descartes ontology where both the
  mind and the body are substances.
• Leibniz consider the world as consisting merely
  of one type of substance, though, there are
  infinitely many substances of that type.
• These substances are partless, unextended
  entities, some of which are endowed with thought
  and consciousness, while others found the
  phenomenality of the corporeal world (Leibnizs
  idealism).

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• Since Leibniz held that there is only one type of
  substance in the world, the mind and the body are
  ultimately composed of the same kind of
  substance.
• 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.

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• The human mind and body are causally insulated
  from one another.
• 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.
• Mind/body relation
• The mind expresses its body by perceiving it
  (perception is a species of expression).
• Vs. Descartes, we have unconscious perceptions.

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Mind and Language

• Leibniz, like contemporary cognitive scientists,
  saw an intimate connection between the form and
  content of language, and the operations of the
  mind.
• 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).

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• This view led Leibniz's to formulate a plan for a
  universal language. I.e., an artificial
  language composed of symbols, which would stand
  for concepts or ideas, and logical rules for
  their valid manipulation.
• He believed that such a language would perfectly
  mirror the processes of intelligible human
  reasoning.
• Leibniz came close to anticipating artificial
  intelligence.

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• Natural language
• 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))

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Nativism Innate Ideas

• Main argument for nativism the human mind is
  causally independent from any other substance
  except God.
• This argument is a renewal of the Platonic and
  Cartesian doctrine.
• Like in Platos system, innate ideas should
  solve problems in the philosophy of mathematics.
  E.g. to explain how a priori knowledge is
  possible (cf. Socrates majeutics).

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idea

• To be understood in a dispositional way.
• 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.

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• Objects of ideas, i.e. the semantics of ideas.
• 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 doesnt follow that I have an
  idea of it. For a round-square is an impossible
  object.

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• An idea in ones mind/soul is simply another
  property of that monad.
• 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 ones senses.

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• 3 levels of reality
• 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).

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• Leibnizs notion of ideas allows him to criticize
  Descartes ontological argument.
• 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
  Leibnizs sense, i.e. as a disposition (and that
  Descartes builds Gods existence into the idea
  itself).

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Metaphysical argument for nativism

• Argument
• Pre-established harmony the human mind with all
  other substances is causally self-sufficient.
• From this Leibnizs 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

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• What the argument proves is that nothing reaches
  the mind from outside.
• 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.

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The introspection argument for innate ideas

• Leibniz claims that if (as Locke concedes) we
  assume that some ideas can be acquired from
  reflection (introspection), then these ideas must
  be innate.
• Two criticisms of this argument
• 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).

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• 2. It merely proves that metaphysical ideas
  (substance, motion, ) are innate. It doesnt
  prove that mathematical ideas are innate since
  we dont reach them by introspection. And
  mathematical ideas play a central role in
  Descartes and Leibniz .
• This critique is a good one. The first can be
  answered.
• Answer to critique 1
• 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.

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Nativism the argument from knowledge

• Like Plato in the Meno, Leibniz thinks that we
  can argue for the innateness of geometrical ideas
  because of our capacity to know necessary truths.
• See Socrates maieutic (the philosopher like a
  midwife).
• Leibniz doesnt accept, though, Platos theory
  of reminiscence, i.e. that we remember
  ideas/forms from a previous life.

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• Platos argument proves only a dispositional or
  virtual form of nativism.
• In mathematics we make knowledge claims that it
  is necessarily true that p. E.g. it is necessary
  true that 2 2 4.
• 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

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• Innate principle play a normative role, not an
  explanatory one.
• Why innate principles must be true? Why theyre
  not a bunch of lies?
• Descartes can answer in appealing to Gods
  benevolence God is not a deceiver.
• Leibniz cannot answer this way since he
  dismisses Descartes appeal to God in order to
  solve epistemological problems.

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• Leibnizs answer
• 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 Gods
  benevolence, Leibniz appeals to the isomorphism
  between our min and Gods mind (monads are the
  mirror of God).

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Locke and Malebranches challenge

• They both, from different perspectives, challenge
  Leibnizs view that the mind is self-contained, a
  self-sufficient entity.
• Locke (book 1 of Essays)
• 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.

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• 1. If nativists assume (i) they are asserting
  something empirically false.
• New-born babies show no sign of actual knowledge
  of necessary truths they dont know the truths
  of logic and mathematics.
• 2. If nativists assume (ii) they say something
  trivially true.
• All knowledge and concepts that one ever comes
  to entertain would be innate.

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Leibnizs defense of nativism

• Leibniz claims that there is a third possibility
  that Locke didnt consider.
• 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.

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• The human mind, from birth, has a certain natural
  grain.
• It is differentially predisposed toward
  employing certain principles and thinking in some
  ways rather than others.

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• Leibniz opposes Lockes image of the tabula rasa.
• 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)

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• The disposition is more than a potential (and
  less than an actuality).
• Leibniz shares with Descartes the view that
  dispositions play a central role in the defense
  of innate ideas.
• 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. Quines gavagai example).

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• How can dispositions help in unpacking claims
  regarding mathematical and logical truths?
• Leibniz claims that the rules of logic (e.g.
  propositional calculus) work within the grain of
  the mind.
• How do we explain, then, than most of the time
  people make fallacies in their reasoning?

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• Malbranches criticism
• 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.

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• Cf. Fragility
• If
• fragility the disposition to break given some
  circumstances
• then,
• we explain the glass breaking on the hard floor
  by its fragility.

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• The explanation is merely circular/empty the
  glass brook when dropped in such circumstances
  because it has the property of breaking in such
  circumstances.
• The same with a thought.
• If having the idea of a triangle is a
  disposition to have it in such circumstances/stimu
  lus, then one has an idea of a triangle when
  facing such circumstances/stimulus.

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• Leibnizs possible reply (he didnt directly
  address Malbranches critique).
• 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.