Midterm Flashcards
(64 cards)
Premise
- The statements supporting the conclusion
- Meant to provide reasons for believing that the conclusion is true
- Relation between premises and conclusion is what matters
- They are statements (or claims) that can be true or false
Modus Tollens
- Type of argument
- Denying the consequent
- A valid form
- Any argument using this form must be valid
- Ex:
1. If P, then Q
2. N (not) Q
3. N P
Modus Ponens
- Type of argument
- Affirming the antecedent
- Any argument having this form is valid
-Ex:
If P, then Q
P
Q
Syllogism
-Type of argument
-Ex:
All As are Bs
X is an A
X is a B
Deductive Inference
- Central logic is validity
- Intended to give logically conclusive support to their conclusions so that if the premises are true, the conclusion absolutely must be true
- Distinguishing validity from truth
- Types: Categorical syllogism, ponens, tollens
- Key Point: form or structure of argument determines validity or invalidity
Inductive Inference
- Type of non-deductive reasoning
- NOT valid but still rational
- Uses Probability (if premises are true, conclusion is probably true)
- Inference to next case
- Universal generalization
- Relies on similar, observed cases, to infer that the same event or property will recur in as yet unobserved cases
Soundness
- Valid AND true premises
- A good deductive argument
- When a valid (deductive) argument has true premises, it is a good argument
- (strong is for inductive arguments)
Validity
- If the premises are true, the conclusion must be true
- A relation among between among statements
- ARGUMENTS can be valid
- A valid argument can have:
- true premises and a true conclusion
- one or more false premises and a false conclusion
- one or more false premises and a true conclusion
- Only possibility ruled out by validity is that the argument have true premises and a false conclusion
Equivocation
-Type of fallacy that is assigning two different meanings to the same significant word in an argument
- The word is used in one sense in a premise and in a different sense in another place in the argument
- Makes argument invalid
- The switch in meaning can deceive reader and disrupt argument, rendering it invalid or weaker
- Ex: “All sharp things can be used to cut - UNLV students are sharp.”
Begging the Question
- Type of fallacy that is trying to prove a conclusion by using that very same conclusion as support
- You smuggle into one of your premises, your conclusion; presuppose conclusion to explain conclusion
- Arguing in a circle
- ”X is true because X is true”
- Argument that uses conclusion as explanation to say conclusion is correct
- Ex: “I believe in God because the Bible says so.”
Perfections
- ”Great-making” qualities
- Properties that make something better
- Something that makes something worthy of worship or awe
- Key idea: existence in reality is a perfection
Ontological Argument
- An argument that tries to demonstrate God’s existence by logical analysis of the concept of God
- Argument for the existence of God that is the most intriguing
- Anselm’s argument:
1. God exists in the understanding
- God is a possible being
- If something exists only in the understanding and could have existed in reality, then it could have been greater than is is
- Suppose God exists only in the understanding
- Then God might have been greater than he actually is
- God is a being than which a greater is possible
- The being than which no greater is possible is a being that which a greater is possible
- It must be false that God exists only in the understanding
- Therefore, God exists in reality as well as understanding
Impossible Things
- Things that cannot exist in reality or even the understanding
- Ex: Round Square
- (Ex of Possible: Unicorns)
A Priori vs. a Posteriori
- A Posteriori: based on observations; based on premises that can be known only by means of experience of the world
- Ex: that there is a world, events have causes, and so forth
- Ex:Cosmological and teleological arguments
- A Priori: do not need observations; does not depend on such premises; rather, it rests on premises that can be known to be true independently of experience of the world: One need only clearly conceive of the proposition to see that it is true
- Ex: Ontological argument (only argument for God that is a priori)
Reductio Ad Absurdum
- Assumes negation of conclusion to establish conclusion
- Show negation of thesis leads to contradiction
- Strategy Anselm employs in his argument
- Begins with a supposition that is contradictory to what one desires to prove and then one goes about showing, together with other certain or self-evident assumptions, yields a contradiction, which in turn demonstrates that the contradictory of the supposition MUST BE TRUE
Guanilo’s Island
- Objected Anselm’s ontological argument
- The existence of a fully perfect island is not possible
- Used this because Anselm doesn’t pinpoint what’s wrong, but has suspicion
Principle of Sufficient Reason
- Leibniz’s Principle of Sufficient Reason
- Pinpoint in cosmological argument
- All individual things and events have an explanation
- Sometimes difficult finding cause, but we know there’s an explanation
- All individual things and events have an explanation
- All positive facts have an explanation
- There is an explanation for every aspect and condition of the world (not brute facts)
- Every fact has an explanation
- Ex of negative fact: “these glasses are not the number 7”
- All positive facts have an explanation
- Overall, every event and every positive fact has an explanation
- ”positive fact” is important because then mere existence of the universe requires an explanation
Cosmological Argument
-An argument that tries to show that from the fact that the universe exists, God exists
Fallacy of Composition/Division
- Composition: The fallacy of arguing erroneously that what can be said of the parts can also be said of the whole
- Ex of Composition: “each brick in that wall weighs 10 lbs, so the wall weights 10 lbs
- Division: The fallacy of arguing erroneously that what can be said of the whole can be said of the parts
- Ex of Division: “That wall weights 10,000 lbs, so each brick weighs 10,000 lbs
Unmoved Mover
- Aristotle
- Cosmological argument
- The first cause
- God is constantly moving the universe and the mover caused the universe
- God is an uncreated creator; he caused things, but nothing caused him
Teleological Argument
-An argument that tries to show that God must exist because features of the universe show signs of purpose or design
Watch Analogy
-William Paley
- Compares the universe to a watch and claimed that every manifestation of design which exists in a watch also exists in the works of nature
- ”The universe as a machine”
-The way in which the universe is supposed to resemble a machine is that parts of nature are seen to be related to one another in the same way as parts of a machine are related to one another
- Helps teleological argument (design argument)
- Answer to Darwinian criticism (evolution provides alternative explanation)
Garden Analogy
- Flowers growing in perfect rows, so you think there must be a gardener. Think of eye and its perfect function, and we think there must be an intelligent creator who made it, but then you investigate, and you find that…
1) These flowers need a specific mineral
2) The mineral often appears in the soil in rows
3) You dig in the soil and find that the minerals ARE in rows
4) The seeds are scattered all over the place
5) Now, you have an alternative explanation that’s 100% natural - Eye was formed with randomness (most were useless combinations) and selected a specific combination, so now, perfectly explains why eye seems designed (Darwin’s explanation)
- Helps “Inference to Best Explanation” argument (teleological argument)
Inference-to-best-explanation
- A form of inductive reasoning in which we reason from premises about a state of affairs to an explanation for that state of affairs
- Appealing to best hypothesis