An Enquiry Concerning Human Understanding

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An Enquiry Concerning Human Understanding

• Philosophy 1
• Spring, 2002
• G. J. Mattey

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British Empiricism

• John Locke (1632-1704) adopted Descartess new
  way of ideas
• Locke rejected innate ideas, claiming that all
  ideas come from experience
• He also held that all that can be known on this
  basis is our own existence, the existence of God,
  and that of material things we are now sensing
• George Berkeley (1695-1753) denied the existence
  of matter altogether

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David Hume

• Born 1711
• Scottish
• Historian of England
• Popular essayist
• Worked in diplomacy
• Denied teaching position due to charges of
  atheism
• Died 1776

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Humes Contributions

• Argued for moderate skepticism in theoretical
  matters
• Cause and effect
• Personal identity
• Existence and nature of God
• Tried to base geometry on sensory experience
• Originated the belief-desire account of human
  action
• Proposed an ethical theory based on the feeling
  of sympathy

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Species of Philosophy

• There have been two prevailing species of
  philosophy
• A popular philosophy, which is easy to comprehend
  and which motivates people to act virtuously
• An abstruse philosophy, which is difficult and
  which seeks to understand the principles
  governing human nature

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Reason and Action

• Profound research is thought to be useless, and
  it produces uncertainty that leads to melancholy
  and rejection
• It cannot be sustained in a social setting
• Merely acting, while ignorant, is despised
• The mind needs rest from constant activity
• The best life is a mixed one
• Be a philosopher, but, amid all your philosophy,
  be still a man

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Metaphysics

• Metaphysics is accurate and abstract
• Accuracy is advantageous to art, business,
  government, law, etc.
• The study of metaphysics is pleasurable to those
  with vigorous minds
• But its obscurity harbors error by giving shelter
  to superstition
• This is why metaphysics must be pursued, yet in
  an easy manner

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The Powers of the Mind

• An investigation of the powers of the mind will
  show it unsuited for the investigation of remote
  and abstruse subjects
• It is satisfying in itself to map the powers of
  the mind
• Can we discover the fundamental sources of these
  powers?
• Since they have not been discovered yet, it must
  be hard to find them

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The Origin of Ideas

• Impressions are original, lively thoughts
• Sensations
• Emotions
• Desires
• Volitions
• Ideas are less-lively copies of impressions
• All (or nearly all) ideas are copies of
  impressions
• The test for validity of an abstruse
  philosophical idea is to find the impression of
  which it is a copy

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The Association of Ideas

• Ideas and impressions occurring in the mind are
  connected by general principles
• Even the most disorganized thought has some
  thread of order in it
• There are three such principles
• Resemblance
• Contiguity
• Cause and effect

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Relations of Ideas and Matters of Fact

• Mathematical sciences, which are intuitively or
  demonstratively certain, concern only relations
  of ideas
• They are based on mere thinking
• Other objects of investigation concern matters of
  fact
• There is no contradiction in denying them
• So what evidence do we have of their truth?

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Cause and Effect

• The senses and memory attest to the real
  existence of things
• This testimony is extended by reasoning about
  cause and effect
• This reasoning moves from a present fact to a
  remote fact
• It does so through the presumption of a real
  causal connection between the facts
• But how is this connection known to hold?

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Cause and Effect Discovered through Experience

• We do not know a priori what effect will follow
  from a given cause
• Only experience allows us to discover the
  connection, e.g., that bread nourishes
• Custom conceals this reliance on experience
• We cannot without experience predict a particular
  effect
• Nor can we discover the general relation

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Ultimate Causes Unknown

• The best we should hope for in natural philosophy
  is to reduce the causes of natural phenomena to a
  few (gravity, cohesion)
• These are based on analogy and observation
• The causes of these causes are beyond our reach
• Mathematics cannot uncover causes

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Causal Reasoning

• Causal reasoning is based on experience
• What justifies our use of experience to draw
  conclusion about matters of fact?
• We connect sensible qualities with secret
  powers bodies with the perceived qualities of
  bread have the power to nourish us
• By what reasoning do we extend the power
  observed in one piece of bread to an unobserved
  piece?
• There is no apparent medium to connect the two

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The Missing Link

• There can be no demonstration connecting the
  observed with the unobserved
• The opposite can always be conceived
• So the connection could only be established by
  probable reasoning about matters of fact
• All such reasoning is based on similarity
• What is the medium connecting the similar to the
  similar?

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Begging the Question

• It might be said that experience is the required
  medium
• It could serve as a medium only if the future
  resembles the past
• We infer that the future resembles the past only
  on the basis of experience
• But this use of experience then requires the
  premise that the future resembles the past

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Is There an Inference At All?

• We do not know how to support the inference from
  the observed to the unobserved
• It may be that there is no inference at all
• A child learns at once to avoid a hot surface,
  and no inference seems to be involved

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Skepticism

• Skepticism talks of doubting, suspending
  judgment, refraining from rash conclusions
• As such, it does not ally itself with any of the
  passions, except love of truth
• For this reason, it is stigmatized as libertine,
  profane, and irreligious
• But skepticism about the basis of causal
  inference does not undermine ordinary reasoning

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Custom and Habit

• The reason we make judgments based on experience
  and refrain from then when lacking experience is
  custom or habit
• This allows us to conjoin things which in
  themselves are dissimilar, such as weight and
  solidity
• Custom is the great guide to human life
• It always terminates in a present sensation or
  memory

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Belief

• The difference between belief and fiction is not
  to be found in the idea itself
• Instead, it is a feeling found in belief alone
• It gives ideas more weight and influence, makes
  them appear of greater importance, enforces them
  in the mind, and renders them the governing
  principle of our action

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Mechanisms of Belief

• Belief is an intense idea of something
• In the case of the relation of cause and effect,
  the idea of one thing is intensified in the
  presence of the idea of another
• The same holds for resemblance our idea of a
  friend is intensified by a picture of him
• And also for contiguity my idea of my home is
  more intense upon my approach
• Custom accounts for all these phenomena, in
  harmony with nature

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Probability

• Although there is no chance in the world, our
  ignorance of causes makes it seem as if there is
• Our beliefs about chances reflect the intensity
  of our ideas of each alternative
• Our ideas of causes vary in intensity with the
  number of cases
• If enough cases concur, there is belief

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Necessary Connection

• Mathematics deals with clear concepts, but with
  complicated inferences
• Metaphysics deals with obscure concepts, though
  its inferences are short
• The most obscure ideas in metaphysics are those
  of power, force, energy, or necessary
  connection
• What impression lies behind them?

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Sources of the Idea

• Ideas of external objects do not reveal necessary
  connections
• We experience only the conjunction the power
  remains hidden
• It is thought that experience of our willing a
  change in ones body reveals a power
• But this pretension will be exploded

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Willing to Move

• The consequences of our willing can only be
  determined through experience
• We do not know how mind and body are connected
• We lack control over some parts of our body
• We do not bring about movements directly

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Willing Ideas

• It is also thought that will is the power to
  produce or control ideas
• But we lack an impression of this power
• We do not know how the mind brings about ideas
• We lack control over some ideas
• Our control is variable

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Occasionalism

• Nicolas Malebranche and others claimed that only
  God is a cause, and alleged causes are only
  occasions for Gods causality
• This view detracts from Gods power
• It also has philosophical defects
• It too-boldly carries us beyond experience
• We are as ignorant of any causal power in the
  mind as in bodies

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The Origin of the Idea of Power

• All we discover through experience is
  conjunction, not connection
• Do we, then, have no idea of power at all?
• When there is constant conjunction, we assert
  that there is a causal connection
• The only similarity in the conjunction is
  repetition of similar instances
• We feel a transition, and this feeling is the
  impression from which the idea of power is copied

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Causality Defined

• A cause can be defined in terms of the feeling of
  transition
• One definition of cause is an object followed by
  another and whose appearance always conveys the
  thought to that other
• This transition is explained in terms of custom
  and habit

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Antecedent Skepticism

• Descartes sought to prevent error and thus
  doubted what he could
• By bringing his own faculties under doubt, he
  prevented any possibility of removing doubt
• If there were any self-evident starting point for
  recovery from doubt, its application would
  involve the faculties in question
• A more moderate version is useful to begin with
  what is self-evident and make only small steps

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Consequent Skepticism

• Some skeptics focus on the actual deficiencies in
  our mental faculties
• Sensory illusion is generally cited
• But it can be corrected through reason
• A more difficult problem lies in the natural
  tendency to suppose that the images of the senses
  are external, independent objects

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Doubting the Senses

• Philosophy shows that the images of the senses
  are distinct from independent objects
• At best, they are copies of those objects
• But the claim of resemblance cannot be justified
• We do not know the origin of the images
• And we have no way to compare the two
• Appeal to God is ruled out
• So the teachings of nature are incorrect, and
  those of philosophy lead to skepticism

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Primary and Secondary Qualities

• It can be shown that the claim of resemblance is
  contrary to reason
• We cannot abstract extension from color, primary
  from secondary qualities
• Secondary qualities depend on the senses and
  exist in the mind
• Primary qualities are no different
• So, primary qualities exist in the mind
• All that is left is an unknown something

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Skepticism About Mathematics

• Abstract reasoning involving space and time fall
  prey to paradoxes of the infinite
• A real line is divided into infinitely many
  parts, each one of which is infinitely divisible
• But this itself is paradoxical, because the
  initial ideas seem clear, so we are skeptical of
  our skepticism

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Pyrrhonism

• Extreme skepticism would have us doubt all
  reasoning concerning matters of fact
• But this Pyrrhonism is overcome by our need to
  act
• Nothing of any lasting value results from itit
  is mere amusement
• So the skeptic should confine himself to
  philosophical objections into abstract matters,
  such as causality

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Mitigated Skepticism

• Most people are dogmatic, as this is the most
  effective way to bring about action
• Some skepticism might cure them of this
• A just reasoner will always entertain some doubt
  and caution
• Another form of mitigated skepticism restricts
  human investigation to what lies in experience
  (not the supernatural, e.g.)