describe the ways in which philosophical questions differ from questions in other areas of inquiry
- philosophical questions are more general
- they involve clarifying concepts
- provide conditions for the application of concepts (definitions)
- they involve fundamental
questions of justification
- are assumptions made in the world rationally defensible?
the components of an argument
-
premises
- propositions - declarative statements
- give reason to believe conclusion
- true or false
-
conclusion
- proposition - declarative statement
- the statement to be established
- true or false
how deduction, induction, and abduction differ
- deduction
- truth of conclusion is guaranteed by the truth of the premises
- conclusion must be entailed in the premises (limitation)
- conclusion is a deductive consequence of the premises
- valid or invalid
- inductive/abductive inference
- conclusion can go beyond the premise
- conclusions can never be stated as true, can be said to be likely based on truth of premises
-
inductive
- results of experiment that can be replicated
-
abductive
- formulating an explanation of why something occurs
- many times explains something cannot see
explain deductive arguments virtue / limitation
- virtue
- the conclusion is absolutely guaranteed by the truth of the premises if argument valid
-
limitation
- the conclusion must be say things stated in the premises
definition of deductive validity
IF the premises WERE true, they would provide an absolute guarantee of the truth of the conclusion
test for validity / invalidity
- isolate structure of the argument
- discard content
- determine
-
IF these premises are all true, is the truth of the
conclusion GUARANTEED?
- yes = deductively valid
- is
there ANY possibility that the conclusion could be
false?
- yes = deductively invalid
-
IF these premises are all true, is the truth of the
conclusion GUARANTEED?
invalid argument form:
If P then Q
Q
then P
good arguments vs bad arguments
good argument
- premises gives reason to believe the conclusion is true (rationally persuasive)
- valid - truth of premises guarantees the truth of the conclusion
- true premises
bad argument
- does not give reason to believe the conclusion is true (not rationally persuasive)
circular arguments
- arguments that do not provide reason to believe the conclusion if they do not already believe it
- deductively valid argument
- ex: horses are animals, therefore, horses are animals
what influences the strength of an inductive argument?
- sample size (more = better)
- randomization (more = better)
abductive arguments and explanations
- are inferences to the best explanation
- involve inferring what cannot be observed
- formulate an explanation as to WHY something occurs
- CANNOT ever say something is true/conclusion is true
- can ONLY DISCONFIRM/DENY/ say something is false if predictions false
- ex: Mendel's discovery of genes
theoris and predictions: how are true and false predictions evaluated?
- can NEVER confirm a prediction/theory is true based on predictions
- can DISCONFIRM if it makes false predictions
- truth of theory does
NOT follow deductively from truth of the prediction
- would be INVALID
truth and falsity
-
truth
- is objective and true for everyone independently of anyone's opinions
- true proposition - world IS the way the proposition says it is
- false proposition - world is NOT the way the proposition says it is
true for me
- NEVER say this
- misleading
- is a misuse use of the truth predicate
- TRUTH is true for everyone and is objective, existing outside of anyone's opinions/beliefs
- truth only relies on the reality of the subject
- saying "true for me" just means you believe something
- this is subjective thinking
definition of God
in philosophy: ALL
- powerful (omnipotent)
- knowing (omniscient)
- good (omnibenevolent)
Aquinas' first four ways
- argument of motion
- first mover (God)
- caused first motion in natural world
- argument of
causality
- God caused first event in natural world
- argument of contingency
- God is a necessary being
- contingent things exist, so a necessary entity exists
- argument of degrees
- God has all possible degrees for all properties
- objects show degrees of properties, so object must exist with all properties to maximum degrees
the birthday fallacy (know how it is committed in arguments)
- every person has a birthday, a day which he or she was born
- there is a single day that is everyone's birthday
arguments:
- motion
- says objects are caused to move by other objects (not themselves)
- and then says entity (God) caused the motion of the first moving object that exists
- fallacy - does not show there is ONE first movement (birthday fallacy), but only shows there is at LEAST one
- causality
- says every event has a cause, and cannot cause itself
- conclusion: there is an entity (God) that caused the first event
- fallacy - does not show there is ONE first cause (birthday fallacy), but only shows there is at LEAST one
- contingency
- says each contingent thing has a time at which it fails to exist
- says this means that there would be an empty time in the past, and therefore the world would be forever empty
- fallacy - even if contingent objects necessarily have a time they failed to exist, cannot conclude that there is 1 time where there is NO objects (birthday fallacy)
- degrees
- says objects have properties to degrees
- so then there must exist an object with properties to all possible degrees
- fallacy - even if there is a maximum exemplar of moral goodness, CANNOT conclude that there is a single entity (birthday fallacy) who is all-PKG just from these premises
contingency vs. necessity
-
contingency
- depends on something for it to exist (could have failed to exist)
- does not exist in all possible worlds
-
necessity
- does not depend on something else for it to exist (could NOT have failed to exist)
- DOES exist in all possible worlds
contingent vs. necessary propositions
-
necessary propositions
- propositions that are true in all possible worlds
- arithmetic truths, shapes, etc.
-
contingent propositions
- are NOT true in all possible worlds (true in some/false in others)
- ex: this binder is blue
Aquinas' argument from design vs. Paley's argument from design
-
Aquinas' arguments
- deductive arguments
- none work - all have fallacies
-
Paley's argument
- abductive
- might work
- Hume's arguments do not do anything because he thought it was an inductive argument