Philosophy and ethics

• What is philosophy?

  • ‘Love of wisdom’
  • pursuit of truth
  • the study of fundamental and general questions
  • ”a defence against the intimidations of dogmatism”
  • ”a framework for the operation of intelligence“
• What does it mean to be dogmatic?

  To be dogmatic means to have a rigid, inflexible adherence to a set of beliefs or principles, often without considering alternative perspectives or evidence.

  • inclined to lay down principles as undeniably true
• Defining ’argument’


  A statement or set of statements put forward so as to justify, prove, or provide reasons as to why we believe/agree with something
• propositions


  typically expressed with the use of declarative sentences. declaratives are statements capable of being true or false
• varieties of sentence form include

  exclamatory, interrogative and imperative
• What are the building blocks of arguments?

  Propositions
• what sentences express if something can be true or false

  only declarative sentences express something can be be deemed true or false.
• conclusion:

  the claim (proposition) that the arguer wants to justify, prove, or persuade you to believe
• premise:


  the claim(s) that are intended to provide the justification, support, proof of the conclusion.
• inference indicators:

  words which are used to signal a connection of inference between statements. e.g. because, so
• Premise indicators:

  Signal that a premise in the argument is coming next e.g since, because, for the reason that, given that, firstly etc.
• conclusion indicators:


  signal that a conclusion is coming next e.g thus, therefore, it follows that, hence, so
• Barriers to recognition of arguments:

  • Discrepancy between sentence form and function
  • words that you don’t realise are inference indicators
  • common inference indicators not functioning in their usual way
  • sometimes inference indicators aren’t used at all
  • dense sentences (sentences can be hidden)
  • conclusions that are not made explicit, only implied
  • bad writing
• When you think there us an argument but there isn’t

  1. Someone who quotes or describes and argument but does not themselves offer that argument
  2. an explanation is not, or is not always, an argument E.g. Sandy’s back problems were caused by a car accident
  3. a narrative is not an argument
  4. the use of a conditional “if…then…” statement is not an argument. E.g if the car starts then the batter is full
• arguments

  • seek to bring about the acknowledgement of a fact
  • try to justify their conclusions
• explanation

  • try to cast light on an acknowledged fact
  • Aim to make a claim understandable
• Clarifying the structure of arguments

  1. Read the passage, bracket and number each separable statement
  2. circle any inference indicators
  3. underline conclusion
  4. put the argument into standard form
• what must you do in standardisation?


  make full, comprehensive, sentences
• Separable statements

  • Conjunctions should be separated
  • Don’t separate conditionals “if...then…”
  • don’t separate disjunctions “either…or…”
• Missing premises

  We should only add missing premises if they are:

  • Plausible
  • justifiable in the context of what the author has actually said
  • consistent with the best possible version of the argument under consideration.
• principle of charity


  always interpret someone else’s argument in such a way as to attribute to them the strongest reasoning of their argument.
• Critical reasoning

  arguments have premises, and an inference to a conclusion.

  criteria includes:

  1. premise acceptability
  2. inferential support
• criteria one: premise acceptability

  1. are, or might likely be true; or,
  2. can be assented to (agreed to) for the purpose of the argument and its context

  Acceptable premise X true premise (acceptability of untrue arguments can happen)
• How to define premise acceptability

  1. We need to reason with premises which we aren’t in a position to know whether they are true or false
• when are premises acceptable?

  1. When supported by a cogent sub-argument (a really good argument)
  2. when supported elsewhere
  3. when known to be a priori (“from the first.” Known to be true prior to any observation or experience)
  4. when a matter of common knowledge
  5. when supported by credible testimony
  6. when supported by a proper authority
  7. when provisionally accepted
• a posteriori is after observation


  a prosteriori is used to refer to statements that can only be known to be true after observation or experience
• What is credible testimony?

  Testimony from another person may be acceptable so long as it dies not exhibit one of the following faults:

  • the claim itself is implausible
  • the person making the claim has a poor reputation
  • the content of the claim goes beyond credible evidence.
• when supported by proper authority..

  in certain contexts, claims or statements are rationally acceptable because a reliable authority, such as an expert, has asserted them.

  be careful:

  • a claim must lie within some specific field on knowledge which has recognised standards of expertise
  • the person themselves must be credible and reliable
  • there must be agreement among experts about the claim
• Criterion 2: inferential support


  A matter of how likely the premises -if they were true- would make the truth of the conclusion

  In order to evaluate inferential support, you need to put aside the issue of premise acceptability
• Judging inferential support

  Supposing for that the premises are true, how improbable does this make it that the conclusion is false?

  • If impossible for the conclusion to be false supposing true premises…then the inferential support is complete
  • if it is very unlikely for the conclusion to be false and the support true ... The inferential support is strong
  • if it is unlikely for the conclusion to be false supposing the premises are true… then the inferential is moderate
  • if it is likely for the conclusion to be false supposing the premises are true… and then the inferential support is weak
• judging inferential support examples.

  1. three successive tosses of a coin have each been heads. so, the coin has been tampered with-weak argument
  2. the coin has now been flipped six times, heads. so the coin has been tampered with - unlikely
  3. thirty tosses are all heads so its been tampered with -strong
• Linked and convergent support

  • Linked: each claim of set premises provide no independent support for the conclusion, but, when taken together, they jointly support the conclusion
  • convergent: the claims among a set of premises provide some degree of support for the conclusion when taken separately. Each premise in the set provides a separate reason for thinking that the conclusion is true.
• Complete support


  The idea of an argument whose premises -if they were true- would make certain the conclusion.

  If the premises are true, then necessarily the conclusion is true as well

  it is not possible for the premises to be true and the conclusion false
• deductive validity

  when it is logically impossible for the premises to be true and the conclusion false, we say that the argument is deductively valid.
• logically impossible


  …the attempt to describe a situation in which the premises are true and the conclusion false involves a contradiction.
• Terminology for overall evaluation of arguments:

  Cogent argument: one that has both rationally acceptable premises and at least one strong inferential support

  Sound argument: one that has both true premises and is deductively valid
• Implications of a cogent and sound argument:

  Must satisfy both criteria
• Deductive validity and formal logic


  ”Mr shader was born in 1987 and is still alive today, therefore, he was alive when the Berlin Wall came down”

  Valid in virtuous form
• Modus Ponens

  The way that affirms by affirming.

  1. e.g. “Tom is a member if the Mensa society” (if antecedent, then consequent)
  2. ”Tom is a member if the mensa society“ (antecedent)

  so 3. Is consequent

  if A (antecedent) then B (consequent)
• Modus Tollens


  The way that denies by denying.

  1. if the petrol fire was caused by John’s cigarette, then john lit his cigarette before the petrol caught alight.
  2. john did not light his cigarette before the petrol fire

  Therefore john didn’t light his cigarette before the petrol fire

  if not A then not B.