5 Leibniz (1646-1716): Metaphysics

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5Leibniz (1646-1716) Metaphysics
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• TAs office h.
• none

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Introduction

• A good introduction to Leibniz
• Jolley N. (2005). Leibniz. Routledge
• Leibnizs New Essays free at
• http//www.earlymoderntexts.com/f_leibniz.html

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• The only published works of Leibniz attempts to
  reconcile philosophy with Christian doctrine. His
  most famous published book, Theodicy, promised an
  explanation of the existence of evil in a world
  created by a being who is perfectly good.
• Leibniz was also a great logician.
• He considered the theory of truth, not religion,
  as the starting-point of philosophy.

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• Main (philosophical) works
• Because of his diplomatic engagements he didnt
  published a systematic work like other
  contemporary philosophers (e.g. Descartes,
  Locke, ). He published only one book. Other
  books have been published after his dead.
• Lot of letters/correspondences with major
  philosophers (Arnauld, Malbranche,)

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• BOOKS
• Discourse on Metaphysics
• (composed in 1686).
• Each substance, is like a whole world and like a
  mirror of God.
• New Essays on Human Understanding
• (composed in 1703-5).
• He didnt publish it because Locke died in the
  autumn of 1704. Lockes essays have been
  published in 1690. This is known to be one of the
  best debate between a rationalist and empiricist
  conception.

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• Essay on Theodicity ( the justice of God.
  published in 1710).
• The only book he published. Defence of the
  justice of God who created the best of the
  possible worlds. It is an attempt to reconcile
  the existence of evil in the world with Gods
  benevolent nature.
• Monadology (composed 1714).
• Monads are spiritual substances created by God.
  They are the basic building block of nature.

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Gods Will and Intellect

• Main Thesis
• Gods mind consists in a will and intellect,
  like the human mind.
• Vs. Descartes
• Descartes argued that it would be a
  contradiction to suppose that Gods will is
  determined to act in one way or another (cf.
  Reply to Sixth Objections, Objection 6).

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• Descartes God doesnt act out of a prior
  conception of what is good or bad.
• Gods acts of will determine what is good or
  bad.
• This allowed Descartes to explain Gods freedom
  in terms of the indifference of Gods will.

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• Leibniz considered this view to be dangerous, in
  that it threatened to make values relative.
• If what is good or bad depends on Gods
  arbitrary whish, what we now call bad could just
  as well be good if God decided so.
• Leibniz proposed instead that Gods intellect
  determines his will.
• God does that which s/he considers to be the
  best.

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• Gods acts are timeless (i.e. they dont take
  place in time)
• One of Leibnizs most basic general metaphysical
  principles, the principle of sufficient reason,
  is based on this supposition.
• Anything that exists is due to the activity of
  God, and God always acts for the reason that it
  is the best.

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• Principle of Sufficient Reason
• For anything that exists, there is a reason
  sufficient to determine Gods will to bring it
  about, i.e., the reason that its existence would
  be for the best.

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• Ontological Economy
• Gods actions follow a principle of economy. God
  acts according to the most economical means to
  bring about the most abundant ends.
• Analogy An architect, for example, will use his
  location and the funds set aside for a building
  in the most advantageous manner, allowing nothing
  improper or lacking in the beauty of which it is
  capable.

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• Gods economy is carried out through the use of
  general rules governing creation.
• Some of these rules are discoverable by us
  humans, and we call them laws of nature. Others
  are hidden. These are in play when there is a
  miracle which violates a law of nature.
• Miracles are not irregular events but conform to
  more general regularities.

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The Metaphysics of Substances

• Critique of Descartes
• A substance must be a genuine unity.
• In Descartes the universe is composed of two
  created substances
• (i) mind whose essence is to think, and
• (ii) body whose essence is to be extended
  (three- dimensional)

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• Body as it is conceived by Descartes doesnt fit
  the bill of being a substance.
• Descartes main problem is that he neglected the
  Aristotelian tradition

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• Aristotles two tests for being a substance
• 1. The linguistic test
• Substances are the ultimate subject of
  predication. Socrates passes the test since we
  can predicate many things of him, while Socrates
  can be predicated to nothing.
• The name Socrates can appear only in subject
  position (cf. singular vs. general terms).
• A substance must be something designated by a
  singular term.

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• 2. The metaphysics test
• Substances are substrata of things. The most
  distinctive mark of a substance is what remains
  numerically the same (cf. Aristotles
  essentialism).
• Numerical identity vs. Qualitative identity
• Socrates the baby is 2 feet tall while Socrates
  the adult is 6 feet tall, yet Socrates is one and
  the same individual.
• Socrates numerical identity cannot correspond to
  his body (res extensa).

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• Leibnizs argument against Descartes doctrine of
  extended substances (res extensa)
• 1. No aggregate is an ultimate subject of
  predication
• 2. An entity whose essence is extension is an
  aggregate
• 3. Therefore, no entity whose essence is
  extension is an ultimate subject of
  predication.
• Since being an ultimate subject of predication
  is a necessary condition for being a substance,
  no entity whose essence is extension is, pace
  Descartes, a substance.

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• Any Cartesian body is composed of other bodies
• Nowhere in Descartes theory of the physical
  world we come to entities which are not
  themselves aggregates.
• Leibniz introduces a stipulative definition of
  substance
• substance df. That which has a true unity
• Therefore, any entity whose essence is extension
  is not a substance since it lacks genuine unity.

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The Logicist Strategy

• All true predication has some foundation in the
  nature of things.
• When the predicate is not expressly included in
  the subject, it must be virtually included in it
  (in esse the predicate is in the subject).
• The subject term must always involve that of the
  predicate. So one who perfectly understands the
  subject notion would also see that the predicate
  belongs to it.

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• The concept-containment theory of truth
• In all true affirmative propositions, necessary
  or contingent, universal or singular, the notion
  of the predicate is always in some way included
  in that of a subject -- or I dont know what
  truth is. (Leibniz, Philosophical Texts, Oxford
  UP 1998 11-2)
• Proper name its not an arbitrary simple tag. It
  expresses a concept like a general term (e.g.
  lemon, gold).
• Hence Cesar crossed the Rubicon is true
  because the predicate crossed the Rubicon is
  contained in the subject concept expressed by the
  name Cesar.

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• Individual substances have complete concepts.
• If one were to know the complete concept of
  Alexander, one would ipso facto also know
  everything there was to be known about the
  universe.
• All relational truths about individual
  substances can be deduced from non-relational
  truths about those substances. (e.g. Mary is
  Tims sister being Tims sister is contained in
  Marys substance )
• Every substance expresses the universe. But only
  God can recognize the whole concept.

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Causality

• The critique of the influx model
• Influx model
• Causal interaction about substances in the world
  must be understood as involving a process of
  contagion.
• When a substance A causes a change in substance
  B, A infects B with one of it properties (i.e. by
  an instance of a property). E.g. when the kettle
  boils the gas infects the water within the kettle.

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• The influx model of causality is (for Leibniz)
  incoherent for it rests on the metaphysical
  fiction that accidents can become detached from
  their own substance and move to other substances.
• There is no causal interaction between
  substances. Leibniz claims that monads (the
  ultimate substances) have no windows.
  Pre-established harmony.
• Causality of creatures is modeled on Divine
  creation.
• Created substances are mirrors of God.

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Ontology

• Created substances
• 1. they are genuine unities
• 2. they are genuinely active and causally
  self-sufficient
• 3. they express the entire universe (and thus
  reflect the divine perfection of omniscience)
• In all these ways substances are mirrors of God
• (Cf. Genesis God made man in his own image).

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• Leibniz abandons the Aristotelian ontology of
  corporeal substances.
• The doctrine of monads is a form of idealism.
• Appearance vs. Reality
• Emphasis (already in Descartes) on the fact that
  appearances are misleading.
• The physical world is, strictly speaking,
  deprived of sensory qualities (e.g. colors, odors
  and taste)

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Monads

• Monad (from the Greek meaning unity) a simple,
  immaterial, soul like, substance endowed with
  perception and appetition.
• Appetition the endeavor or striving in a monad
  by virtue of which it passes from one perceptual
  state to its successor. Appetition explains monad
  dynamicity.
• So simple substances/monads can be sources of
  activity.
• Atomism Monads are the true atoms of nature.

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• Since nothing purely material can be indivisible,
  monads cannot be like atoms traditionally
  conceived.
• Monads qua simple are without parts. Thus they
  cannot be corporeal. They must be immaterial.
• Monads are indestructible, for destruction
  consists in decomposition which is a dissolution
  of a thing into its composing parts (see unity of
  substance).

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• Monads can begin (and end) only by a miraculous
  act of creation (or annihilation).
• If monads are simple, immaterial and
  indestructible, then the building block of the
  universe share certain properties with God (they
  are the mirror of God).
• The building blocks of the universe are all
  mental or soul like entities. They are spiritual
  atoms.

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• Monads are windowless So neither substance nor
  accident can come into a monad from outside.
• All monads express (perceive) the entire
  universe. Yet no two monads are exactly alike.
  They have different points of view.
• Differences in points of view to be analyzed in
  term of the distribution of clarity and
  distinctness over their perceptual states.

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Identity of Indiscernible Leibniz Law

• The notion of point of view allows Leibniz to
  accept the principle of the Identity of
  Indiscernibles (sometimes also known as Leibniz
  law).
• If, for every property F, object x has F if and
  only if object y has F, then x is identical to y.
  
• ?F(Fx ? Fy) ? xy

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• Converse of the Principle the Indiscernibility
  of Identicals
• If x is the same as y, then x and y have all the
  properties/qualities in common.
• xy ? ?F(Fx ? Fy)
• Sometimes the conjunction of both principles,
  rather than the Principle by itself, is known as
  Leibniz's Law.
• x y ? Fx ? Fy

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• The hierarchy of monads.
• 1. God is on top by virtue of possessing
  perceptions that are clear and distinct.
• 2. Human minds are lower. They are high quality
  monads by virtue of (i) possessing reason
  allowing them to entertain eternal truth of
  logic and mathematics and (ii)
  self-consciousness the ability to say I.
• 3. At the bottom we have bare monads. They have
  perceptual states but they are extremely
  confused and obscure. They have no
  consciousness.

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Bodies

• Given Leibnizs ontology of monads (immaterial
  substances) what about bodies or physical
  objects?
• Contemporary materialists can adopt an
  eliminativist approach there is nothing but
  physical substances and, strictly speaking, there
  are no such thing as mental states. Another
  alternative is to claim that mental states are
  reducible to state of the body/brain.

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• Leibnizs reductionism
• Reductionism about bodies.
• Does Leibniz anticipate Berkeleys phenomenalist
  account (esse es percipy), i.e. the view that
  each soul or monad is somewhat watching a private
  film?
• When we say Socrates is sitting we mean that
  the concept Socrates is appearing to us and other
  who are concerned.
• Fa can be translated into It appears to me
  that Fa

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• Leibniz may not be a phenomenalist insofar as he
  claims that bodies result from monads, i.e. that
  bodies are aggregate that result from monads.
• Result from monad what does it mean?
• Resulting. What it is not
• 1. It cannot be a causal relation, since monads
  have only internal causation. Monads produce
  their perceptual state by means of striving or
  appetition, but they dont produce bodies.

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• 2. The resulting relation cannot be one of
  whole to parts. Monads have no parts and bodies
  are not composed of monads.
• 3. Resulting is not identity. Leibniz doesnt
  say that bodies are identical with aggregates of
  monads.
• 4. Resulting is not supervenience, i.e. bodies
  do not supervene on certain sets of monads as
  the goodness of an apple supervenes on some of
  its physical properties.

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• Resulting monads express bodies
• We can correctly say that bodies are founded in
  monads, but not that monads are founded in
  bodies.
• Each body stands in a privileged relation to a
  subset of the totality of monads which has the
  job of well-founding it.

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• Leibniz provides metaphysical foundations for its
  physics.
• The physical forces in bodies (e.g. kinetic
  energy) are grounded in the primitive forces of
  monads, i.e. appetition.
• Leibniz is a reductionist in a looser sense.
• He claims that there really are bodies (such as
  tables and stones). Yet facts about bodies can in
  principle be derived from facts about monads, the
  only true substances in the universe.

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• Is Leibniz inconsistent in claiming that the only
  substances of the universe are monads and in also
  talking about corporeal objects?
• Leibniz seems to embrace both forms of idealism
  and form of corporeal substances.
• The fact that Leibniz continues to speak of
  corporeal substances doesnt necessarily mean
  that he is not committed to idealism. He may be
  seen as offering a form of reductionism.

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• The theory of the substantial bond (vinculum
  substantiale)
• It is something above monads which unifies the
  monads as an organism into a substantial whole.
• An obscure theory (it emerged lately in
  Leibnizs work), which should explain the unity
  of organisms i.e. the difficulty of joining
  different simple substances or monads existing in
  our body to make a unique, to make us.