PHIL 151 History of Modern Philosophy

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PHIL 151 History of Modern Philosophy

• Dr. Martin Godwyn
• Fall 2008
• WEEK 9 Locke, Berkeley and Hume on Substance and
  Causality

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This Week ...

• Last week we examined Hume, and a number of
  metaphysical issues have been bubbling to the
  surface.
• Two central issues concern the nature of
  substance and the nature of causality.
• This week we examine how the empiricists handle
  these issues.

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Substance

• Minds and/or bodies are claimed by dualists and
  monists alike to be a kind or kinds of substance
  (or more colloquially, stuff). But what is
  substance? The concept has a long history in
  philosophy.
• Most of the philosophers covered by this course
  have something to say concerning substance, but
  their views are often so incongruous with each
  other that one might wonder whether they are
  talking about the same thing.

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Primary Substance

• As with many other areas in philosophy Aristotle
  was the first to lay out an account is a more or
  less systematic way.
• Aristotle (in his Categories) talks of primary
  substance as a concrete, individual, persisting
  thing.
• For example a particular rock, house, tree, man,
  or mind.

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Secondary Substance

• Aristotle distinguishes primary substances from
  secondary substances kinds of things (species,
  genera, etc.) to which primary substances belong,
  such as human.
• Individual Socrates, Mt. Baker.
• Kind philosophers, mammals, men, humans, Greeks,
  mountains.
• Individuals belong to many different (sometimes
  nested) kinds. Kinds can themselves be individual
  members of broader kinds.

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Substance vs. Property

• Substance is usually contrasted with properties
  (variously, also called attribute, mode, or
  quality)
• A property is said to be possessed by or inheres
  in some substance.
• Consider The apple is round. Here, the
  property is that of being round, and the
  substance is the individual apple.

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Subject-predicate form

• Notice that any proposition seems to conform to a
  subject-predicate form. The predicate names the
  property that is attributed to something (the
  subject).
• Propositions always say of something that it has
  some property. Thus, all true propositions would
  seem to commit us to two metaphysically distinct
  elements the thing and its properties.

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Change over time

• Another reason for insisting on the metaphysical
  distinction between substance and property is
  that objects persist under change.
• A particular tomato changes its properties from
  green to red as it ripens, all the time remaining
  (in some significant sense) the same particular
  tomato.
• Note Not all philosophers share this intuition.
  Heraclitus was famous for insisting that you
  cannot step into the same river twice, precisely
  because it changes every instant.

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Essence vs. Accident

• Not all change preserves substantial identity.
  Some changes result is the destruction or
  coming-into-being of individual substances.
• Take an atom of mercury and knock a proton out of
  the nucleus and it literally becomes an atom of
  gold. The mercury atom ceases to exist and the
  gold comes into existence.

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Essence vs. Accident

• Properties that something has without which it
  would cease to be that thing, are its essential
  properties (sometimes called attributes).
• Those which can change without affecting identity
  are called accidental properties (sometimes
  called modes).

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Form and matter

• A complication is that it often takes more than
  being some particular collection of stuff (or
  matter as Aristotle calls it) to be a
  particular individual.
• A house and a pile of rubble might be constituted
  by the same basic stuff (bricks, mortar, etc.),
  but the latter is not a house.
• Hence, sometimes form (the relation or
  arrangement of parts) seems to play a central
  role in making something a particular thing.

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Locke on substance

• Locke, in some measure, takes up Aristotles idea
  of primary substance.
• He characterises substances as things subsisting
  by themselves. That is, they do not depend on
  anything else for their existence.
• He thinks of material substances as naturally
  occurring kinds of material (corporeal) stuff.

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Real essence

• Locke distinguishes between real essence and
  nominal essence.
• Substances are metaphysically distinguishable by
  their real essences. A real essence is that
  property or properties that makes it the thing
  that it is and gives it its sensible properties.
• For example, the real essence of water, we now
  know, is being H2O.

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Nominal essence

• A nominal essence is, roughly, how we think about
  a kind of thing what we mean when we use a word.
  These are the properties through which we
  identify something.
• The nominal essence may vary from person to
  person (might include being wet, being a liquid
  at room temperature, etc.).

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Locke on Body and Mind

• Locke extends Descartes analysis of the ideas of
  body and mind by adding in causal motive power
  connecting substance with causality
• Body is an extended solid substance, capable of
  communicating motion by impulse.
• Mind is a substance that thinks, and has a
  power of exciting motion in body, by willing or
  thought. (2.23.22)

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Locke on the Mind-Body relation

• However, Locke remained largely agnostic on how
  or whether matter and spirits were substantially
  related.
• The hypothesis that they are ultimately the same
  substance (with different real essences) or
  ultimately different substances is something he
  thinks cannot be known through experience, and
  hence, cannot be known. (2.13.16-18)

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Substrata

• Locke argues that qualities (properties) cannot
  exist in, as it were, a free-floating way. In
  other words, qualities are ontologically
  dependent on substance onto which they are
  anchored. Qualities are always qualities of
  something.
• Not imagining how ... simple ideas can subsist
  by themselves, we accustom ourselves to suppose
  some substratum, wherein they do subsist.
  (2.23.1)

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What is this substratum

• Locke faces up to an embarrassing and surprising
  consequence of his position.
• 1. Qualities are not the substratum (substance).
• 2. All thought or perception has as its immediate
  object, ideas.
• 3. Ideas are ultimately resemblances of primary
  qualities (in the case of our ideas of primary
  qualities) or the causal result of primary
  qualities in the object (in the case of our ideas
  of secondary qualities).
• 4. Thus, we cannot form any idea of this
  substratum (substance).

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Something I-know-not-what

• So that if anyone will examine himself
  concerning his notion of pure substance in
  general, he will find he has no other idea of it
  at all, but only a supposition of he knows not
  what support of such qualities which are capable
  of producing simple ideas in us ... If anyone
  should be asked, what is the subject wherein
  colour or weight inheres, he would have nothing
  to say, but the solid extended parts. (2.23.2)
• He goes on to liken it to saying the world rests
  on the back of an elephant. What does the
  elephant rest on? The back of a tortoise, etc.

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Stuff without properties?

• Related to this is that it is difficult to see
  how the substratum could itself have any
  qualities. If it did, then there would have to be
  a yet more basic substratum in which those
  properties inhered.
• Thus, according to Locke, substance the stuff
  of which the universe is made would seem to be
  both unthinkable and to have no properties!

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Berkeley and Hume

• Both Berkeley and Hume reacted against this
  Lockean view of substance and thought his
  position untenable it implies a material
  something I know not what to use Lockes own
  words.
• Berkeley, as weve seen, focussed his attack on
  the Lockean idea of material substance, and
  argued that the very idea was incoherent, but he
  still kept that idea of mental substance pure
  minds as that in which ideas inhere.

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Humes view on minds

• Berkeley, therefore, is not opposed to the notion
  of substance as such only material substance
  external to the mind. He seems quite comfortable
  with the idea of mental substance (minds, in
  other words) as the substance in which ideas
  inhere.
• Hume argued that Berkeley should have gone one
  step further. Mental substance is as incoherent
  (from an empiricists perspective) as is material
  substance.

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Humes bundle theory of mind

• Thus, Hume has no time for Berkeleys half-way
  house what goes for Lockes corporeal substance
  goes for mental substance too
• When I enter most intimately into what I call
  myself, I always stumble on one particular
  perception or other, of heat or cold, light or
  shade, love or hatred, pain or pleasure. I never
  can catch myself at any time without a
  perception, and never can observe any thing but
  the perception. (Hume, Treatise of Human Nature,
  Book 1 part 4 section 4)

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Bundle theories

• Just as Berkeley thought of matter as just
  bundles of ideas, Hume thought of minds, for all
  we can know, are the same.
• Bundle theories reject the claim that properties
  require some metaphysical stuff to inhere in.
• On such a view, there neednt be any substrata or
  substance, there might only be bundles of
  properties that, so to speak, hang around
  together. The world would be made of properties,
  not stuff.

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Knowledge of mental substance

• Berkeley suggests that we nevertheless have a
  notion of mind or spirit as a causal power.
• What he seems to mean by this is that we
  understand words such as mind or soul as a
  coherent metaphysical possibility of causal
  power. Even though we do not directly perceive
  it, Berkeley seems to think the notion of it is
  coherent. By contrast, Berkeley argues, the idea
  of material substance is not coherent.

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A rationalist concession?

• Moreover, Berkeley suggests, this notion is known
  immediately and reflexively. (Locke makes a
  similar suggestion).
• A rationalist critic might suggest that the
  Berkeleyan notion is, to all intents or
  purposes, precisely what rationalists call
  objects of the understanding i.e., concepts
  understood by reason rather than sensation.
  (Compare Descartes on the 1000-sided chiliagon
  (Med 6))

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A problem with such views

• Is Hume right? A deep puzzle for bundle theories
  is accounting for why properties hang around
  together at all. Doesnt that fact require some
  explanation? Isnt the claim that the ideas
  inhere is a single substance the simplest
  explanation?
• Why does (say) the colour and the weight of the
  green apple not simply come apart and occupy
  different portions of space if there is not
  something in which both these properties inhere?

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The active mind

• Perhaps Berkeleys strongest argument for minds
  suggests that ideas of sensation or perception
  are entirely passive and inactive
• there is nothing of power or agency included in
  them. So that one idea or object of thought
  cannot produce, or make any alteration in
  another. (273)
• Therefore, ideas are not, strictly speaking, the
  cause of anything. To explain how ideas come into
  being we require a mind a mental substance to
  activate and configure ideas.

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Other minds

• Berkeleys theory of minds as the sole causal
  force also allows him to defend himself against
  charges of solipsism.
• Solipsism, recall, is the view that all that
  exists is oneself ones own mind and its
  contents. Berkeley, by contrast, thinks that
  there are other minds but why?

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Other minds

• Berkeleys argument appears to be an inference to
  the best explanation.
• We perceive bodies (meaning here, ideas, of
  course, not material substance) and their
  behaviour is outside the control of our will.
• The existence of minds outside of ourselves is
  the best explanation for their behaviour.

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Minds and Ockhams razor

• Why is it the best explanation? Well, we know
  from direct introspection that we can bring ideas
  of imagination into existence by the will of our
  mind.
• Positing another mind that wills our perceptual
  ideas into existence is the simplest hypothesis,
  since, by Ockhams Razor, it requires us to posit
  no additional kinds of entities other than what
  we already know to exist minds.

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Causation

• Thus Locke and Berkeley have very different views
  concerning causation
• Locke Causation proceeds by impulse particles
  (corpuscles) bumping into other particles.
• Berkeley Causation proceeds by the will of
  minds. Either our minds (imagination) or the mind
  of God (perception).

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Causation

• Humes account of causation is complex.
• Recall Humes arguments concerning our perception
  of causation. Hume argues that we cannot perceive
  any necessary connexion (i.e., a causal
  relation) between events A and B, no matter how
  hard we look.
• All we can ever perceive in one event happening,
  and then contiguously in time and space
  another event happening, but we never experience
  any causal connection connecting the two events
  or objects together.

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What is a cause?

• In addition, Hume argues that our tendency of
  believing in cause and effect relation is
  therefore a product of our natural mental habits.
• This conclusion forces Hume to adopt a very
  thin notion of causation indeed, Hume gives
  us at least two (and arguably three)
  substantially different definitions of causation.

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Humean causation

• Hume defines causation as
• 1a an object, followed by another, and where
  all the objects similar to the first are followed
  by objects similar to the second. 1b Or, in
  other words, where, if the first object had not
  been, the second never had existed. ... 2 an
  object followed by another, and whose appearance
  always conveys the thought to that other. (356)
• These Ill refer to as the constant
  conjunction, the counterfactual and the
  psychological definitions of causation,
  respectively.

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The psychological definition

• 2 an object followed by another, and whose
  appearance always conveys the thought to that
  other
• Definition (2), whether adequate or not, seems to
  be nothing more than a description of human
  habits of thought.
• But for Hume, there is nothing odd about this.
  Humes entire approach is intended as scientific
  or experimental and based in how we happen to
  think and our cognitive capacities.

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The psychological definition

• Recall that Hume has argued that we can never
  perceive a necessary connexion between one
  experience and another, and given his empiricist
  commitment to the claim that all knowledge comes
  from experience, it follows that causation is not
  something that we perceive.
• Since no valid reasoning establishes cause-effect
  relations, it must be nothing but the
  psychologically unavoidable result of our habits
  of thought. When we perceive things as being
  constantly conjoined, we just cant help but
  come to expect the effect when we perceive the
  cause.

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The constant conjunction definition

• 1a an object, followed by another, and where
  all the objects similar to the first are followed
  by objects similar to the second.
• The first definition (1a) defines causation in
  terms of what our causal beliefs are actually
  about rather than why we believe in it
  causation is nothing more than a regular
  succession (constant conjunction).

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One damned thing after another

• This view of causation is very deflationary in
  that it strips the notion of causation of much of
  the metaphysical bite that is usually attached
  to it.
• Consider the following suppose that there is a
  fair die that is rolled 100 times and lands 6
  every time, and also a loaded die that I throw
  and which does exactly the same. Both exhibit a
  constant conjunction.

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One damned thing after another

• On Humes definition (1a), it would seem that
  there can be no metaphysical difference between a
  coincidental correlation between events and a
  lawful correlation between events.
• This strikes many as mistaken. But why? Is there
  a difference between coincidental correlations
  and lawful ones?

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Chance and probability?

• Many peoples intuitions are that the fair die
  landed 6 100 times in a row by chance
  whereas the loaded die did not do so by chance
  at all it was forced to land that way.
• Similar intuitions suggest that the chances of
  the fair die landing 6 100 times in a row are
  very low. But what does that mean? It isnt
  simply a matter of how it actually behaves,
  because it actually lands 6 100 times in a row.

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Counterfactuals

• In other words, the loaded die was caused to
  land 6 by whatever internal feature loads it
  not by the details of my throw.
• In other words, had I thrown the fair die
  differently, it would (or at least could) have
  landed differently. Whereas the loaded die
  would have landed 6 no matter what the details
  of my throw.
• This is where definition (1b)comes to the fore.

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The counterfactual definition

• 1b where, if the first object had not been, the
  second never had existed.
• This definition of causation focuses on
  counterfactuals (contrary to fact relations)
  and are expressed as subjective conditionals
  If A had been so, then B would have been so.
  Notice that this is about non-actual
  possibilities.
• In the case of the fair die, if I had thrown
  the object differently (or at least in a
  relevantly different way), it would have landed
  differently.

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A Humean puzzle

• Curiously, Hume apparently treats his definitions
  (1a) and (1b) as equivalent (in other
  words...). Few join Hume in this, and it is
  perhaps notable that in his earlier and more
  voluminous Treatise on Human Nature, he presents
  versions only of (1a) and (2).