2. argument 1:Deduction
Rationality : our twinguishing characteristic
--what sets us apart from the beasts
Arguments:
PLATO:
How reason should and can function in the human mind
Tripartite soul:
Rational/logic :seeks truth and swayed by facts and arguments
Spirit:emotional part of the self:how your feelings fuel the action
Appetitive /physical desires:drives you to eat , have sex and protect yourself: swayed by tempetitions that are carnal and visceral
Premise: form the sturcture of your argument,offers evidence for your conclusion
Arguments' species:
Deductive;
Inductive;
Abductive;
Argument by analogy;
Reductio ad absurdum
Deductive argument:演繹if the premise is the true ,the argument is true.
Premise 1: all humans are mortal
Premise 2: Socrates is a human
Conclusion : Socrates is mortal
Entailment:a kind of reasoning:one fact leads to another
Deduction:the truth of the premise must leads to the truth of conclusion
Validity is not equal to truth( (if the premises are true ,the conclusion can't be false,but can't prove the conclusion is correct---the premise must entail the conclusion)
Valid argument: the premises entails the conclusion(the reasoning totally stand up)
Invalid conclusion: one of the premises is flawed
Deductive soundness: an argument that's free of formal flaws and defects(premises are all true and valid)
If the argument whose premises are ture and is valid ,its conclusion is guaranteed to be true.
limited---must start with known and true premises which are hard to come by
3. argument 2：induction&Abduction
Induction:歸納 using past experience to make future predictions
Inductive conclusion is likely to be true(the deductive conclusion is gauranteed to be true)
It contains Not certainty but probablity
Limit:
--future not always resemble the past
--every pattern has its outliers
While The world tends to work according to the predictable rules,sometimes the rules are violated
Nelson goodman:GRUE(hypothetical substance )
Grue:anything that's the color green before a certain time t
Grue:green before time t; blue after time t
We are before t now and Emeralds are known to be green and never have changed the color; so inductive reasoning tells us emeralds after time t they will remain green
--inductive evidence can be controdictory and flawed
"when you have elimated the impossible,whatever remians however improbable,must be the truth"
--succinct description
ABDUCTION: 溯因drawing a conclusion based on the explanation that best explains the state of the events, rather than from the evidence provided by the premises
a thought process sometimes decsribed as inference to the best explanation;
preposterous
Interlocutors:people involved in a dialogue ,debete or a conversation
Conspiracy
Counterargument:
Socratic method: learning through a dialectic exchange of ideas,rather than a passive transmission of information
4. the nature of reality
Plato :shadow and reality
A group of people who were sentenced to death were locked in a dark prison and all they could see is a black wall in front of them. Whatever passed before the wall, the persons or the objects, the fire in the prison would cast their shadows on the wall . Because the shadows were all the prisoners could see, they just came to see them as the reality.
Imagine what your view of the world would be like if all you've seen are shadows
You wouldn't know there were sth more, 3d would even be an concept for you.
came to see the things outside the cave are far more real the than the shadow images that he once took for reality.
They have more substance, they have more demensions
Think about how it would feel to suddenly realize that everything you believed just minutes ago turn out to be faint merely outlines of the reality
Our mistake is thinkng the materials or the objects of the ordinary world are the real things
"The pysical world that we think is the most real is actually a mere shadow of higher truth."
5. CARTESIAN SKEPTICISM (neo meet rene descartes)
Skeptic :
Somebody Question whether it is possible to know anything with certainty
Rene :disbelieve everything
An analogy：
Basket of apples: rotten ideas can spread and infect all the ideas around it.Descartes upended the apple basket of his beliefs and decided to start from the scratch.
If he Examine every possible belief carefully and only accept those about which there could be no doubt, and he know He is only believing true things.
Emperical belief: beliefs that we form through the use of our senses.
Local doubts:局部懷疑doubts about a particular sense experience or some other occurrence at a particular point in time
Step out that point and you can check to determine if you've been decieved.but what if everything is a deception?/
Global doubt:
Bertrand Russell: 5 minutes hypothesis
What if the universe was created 5mins ago?
The creator of the universe have designed many elements of the world to make them appear pre-worn so as to seem old.
From dianasour bones fashioned by the creators and planted for us to find to the scars on your knees put there by the creators along with preloaded false memories of how you got it .
--no way to prove that it isn't the case.
Question for Russell : does it matter?
Descartes posited the existence of an evil genius whose life purpose is to deceive us who was clever enough to do it
--(no way to rule out his existence)
Stuck in a radical skepticism
Everything we believe, everything sense experience,every thought,could have been put into our mind by the evil genius who created an illusive world so seamless that we have no way of detecting the illusion.
--Descartes:我思故我在
Meditations on first philosophy"I think, therefore, I am"
Foundational belief:I can doubt my own existence, I can doubt anything , but I can't doubt ,bare minimum, a mind having thoughts
---his existence as a thinking thing
Clear and distinct idea:God exists
6. EMPIRICISM(locke berkeley)
Descartes:immaterical world
Other philosophier/opponents:thinking on its own is not enough
Just know You are thinking doesn't mean your thoughts correspond to the material reality in any raliable way
The nature of reality
Response to skepticism:
1)rationalism :
Descartes--most real things in life were ideas--propositions that can be known through pure reasons
---deductive truth/mathamatical truth
2)empiricism:
principle that most of reliable source of knowledge isn't our ideas or our reasoning ,but our senses
--induction --give us our best shot to get the truth
Split among these two camps:
Plato & Aristotle
Plato :the truth resides in the immerterial world of ideas
Aristotle: whose attention was firmly on the ground
Descarte--his foil:
John Locke
We are born as tabula rasa:blank slate
--all our knowledge are obtained through senses
--he reject the concept of innate ideas that we are born with preloaded certain information about what's good versus bad ,or what's the nature of god
We are born knowing nothing, and instead, all our knowledge comes to us through sense data
Just because Your sense tells you sth,that doesn't mean you can trust it
--dictinction between primary and secondary qualities of all things
(just to figure out whether your sense accurately reflect the outside world )
Primary qualities: belong to the thing itself
phpysical objects themselves have ,they are not in our mind ,they are actually in the stuff
--figure /mobility (width,mass, density…)
Secondary qualities:not real
How we sense(in our mind) get there through the primary qualities
The distinction between the primary and secondary qualiities explained the disagreement that we all have about the perceptions of the outside world
George berkeley:
--use Locke logic against him
--he basicly took empirisim to its logic conclusion, dismantling the whole prpocess of perception to the point that he had to wonder whether anything exists at all
--take apart the distinction between the primary and secondary qualities:
Locke: the primary qualities of the apple is immediately perceivable
Berkeley:you don't perceive some quality of one object while totally disregarding the others
Secondary qualities are not objectively real, they can only be subjectively perceived
--berkeley conclusion: the primary and secondary qualities are inextricably linked --you can't have one without the others
--the primary qualities can't be real either, they are just what you mind makes of things
--there's not such thing as matter. There can' be! instead,there's only perceptions
-- to be ,is to be perceived
--no objects ,noly perceivers(perceivers themselves are not physical form but just disembodied minds)
"we are all set adrift in a world of nothing but thoughts"
Scarying: if anything is just perception so when the perception goes away, there can't be anything left.
Ultimately perceiving: GOD
7. the meaning of knowledge
Assertion & Proposition
Assertion:a liguistic act, either spoken or written that has a truth value
Truth value: state of being either true or false or indeterminate
All declarations have true values. Declarations that assert something about the past or the present are either true or false.assertions about the future are inderminate.
Proposition:the content of the assertion.the underlying meaning of what you're saying.
The proposition is true if it asserts a claim that corresponds to reality.
Propositional attitude:(of disbelief/belief)--depends on whether the speaker believe what he says.
Belief is when you take a propositional attitude of truth.
Knowledge: justified true belief.
Justification: evidence or other support for your belief.
Testimony: one form of justification(in words)
First person abservation: information you acquire through yourself
Edmund Gettier:
Gettier cases: situtions in which someone can have testified true belief but not knowledge.
"you don't know sth if you just stumpled into the right answer."
8 karl popper
Methods like floyd that only served to confirm beliefs were pseudo-science.
And they could be used to prove anything.
It's only by seeking to disprove SANTA'S EXISTENCE that you can demonstrate his unreality.
Science disconfirms
Pseudoscience confirms
Science is prohibitive ,it rules things out.
Every false belief we discover is actually good,because that gets us that much closer to believing only true things.
Popper the only genuine test of a theory is one that's attempting to falsify it.
Irrefutable theories are not scientific.
Testable
Refutable
Falsifiable
Knowledge was about probablity and contingency.
You have to be open to the idea that your beliefs might be false-because that's the only way that holding onto them can really mean anything.
9 philosophy of religion :anselm and argument for god
Anselm:ontological argument本體論論證
god is the best possible thing we can imagine
"God is that than which no greater can be conceived"
2kind of things: one exists in imagination but not in reality; one exists both in mind and reality;(the latter is always better than the former)
god is the greastest thing we can think of.if god exists only in our imagination,it wouldn't be the greatest thing that we can think of ,because god in reality is better. Therefore,god must exist in reality.
--it can be used to prove the anything in imagination.
fallacy謬誤：a flaw in reasoning.sth that weakens or destroys the argument.
Beg the qustion: assume the very thing you try to prove with your argument;
Kant: existence is not a predicate.
predicate謂詞：sth that's said of another object.
Triangle eg: the idea of existence isn't the part of how we define sth.
If god exists,then he must be the greatest being we can imagine,but that does not mean he does exist.
Predicates add to the essence of their subjects,but it can't be used to prove their existence.
What's the difference between an invisible intangible unsmellable,entirely undetectable gardener and no gardener at all.
15 Pascal's wager
pragmatism:實用主義the theory that finding beliefs is less important than finding beliefs that work,practiacally,in the living of your life.
Blaise Pascal(鼻祖）:wager:put your chips on god existing(since it is most practical,no matter god exists or not you will have least loss,given the stakes of not believeing god existence are so high)
'you essentially brainwash yourself into true belief,so that what starts out as self-interest can actually grow into an honest convinction.'
--believeing is practical.(not because god bless his followers,but you can feel the world is safe and being watched by someone and so on)
Fedeism:信仰主義 school of thought that says that religious faith has to come from faith alone.--leap to faith(we have to surrender reason to get to the truth)
'I believe because it is absurd to believe.'-Soren Kierkegaard
Teapot-ists(russel):
opposer:there is no evidence to prove your belief in teapot';
Supporter:there is no evidence to prove that it isn't there.
If you drop reason and evidence all the beliefs are philosophically equal.
We count on evidence and justification to adjudicate between beliefs,to decide what we value.--I have faith in what I choose to have faith in.
16. Existentialism
Plato and Aristotl:
essentialism
Essence :
A certain set of Core properties that are necessery and or essentical for a thing to be what it is
Essential property
--Our essences exists even before we're born.
Good human:adhere to your essences
Your essence give you a purpose.
(we're imbuded(filled) with any essence or purpose"--be challenged by the existentialism)
Nihilism:(Nietzsche)naie_lise_m
Ultimate meaninglessness of life
Existentialism is Not atheism:
1)theistic existentialism :deny teleology(目的論)
refute the notion that God made the universe,or our world,or us, with any purpose in mind.
God exists but not instill ourseleves,our mind ,life ,cosmos with meaning
Existentialism:(Jean-Paul-Sartre)
Existence proceeds essence.
It's up to us to determine who we are and write our own essence
Through the way we choose to live
No actual predetermined purpose
No set path we're supposed to follow
THE ABSURD: search for an answer in an answerless world
--
We're born into a universe in which we,and our world,our action lack any inherent importance.(fundermental compoment)
Absured is Not silly or perposterous
We are creatures search for meanings,but we are abondoned in a universe full of meaninglessness.
Since there is no teleology ,the world wasn't created for a reason,the world doesn't exist for a reason;
If there is no reason for any of this, there are also no absolutes to abide by: no cosmic justice, no fairness,no order,no rules
After WWII:
Terrifying abundance of freedom
Sartre:we are shocking painfully free.
There is no guidelines of our action,each of us is Forced to design our own moral code to Invent a morality to live by
We're condemned to be free.
The authorities you can look to for answers ,but all of the authorities you can think of are fake
Answer:TO LIVE AUTHENTICALLY
Any meaning of your life is given to it by your own.
Bad Faith: a refusal to accept the absurd
The choice,no matter what it is ,is the only true choice ,provided that he made it authentically
:Determined by the value he chooses to accept.
not a bleak picture of the world
Camus:"The literal meanig of life is whatever you are doing that prevents from killing yourself"
The world and your life can have meaning Only if you choose to assign it._
If the world is going to have any of the things that most of us value like justice and order,we just Have to put it there ourselves because otherwise those things wouldn't exist
exhilarating
17 perspectives on death
Socrates :either death is a dreamless sleep or death is a passage to another journey,neither of which is anything to be afraid of.
1:nice sleep and use the rest;2: hang over with the cool people who have already dead.
'socrates recommend spending life looking after your mind,cultivating that part of your body that you'll get to keep forever--if there is an afterlife
By doing it ,when the time comes to you to die, you will actually see death as a benefit because you will never be troubled by bodily things while your mind will be in top form'
Epicurus:reject the idea of afterlife.'we are just our bodies and nothing more'
Death is the cessation of sensation.good or evil only make sense in terms of sensation.so death is neither good or evil.
Things are only good or evil if they feel bad.
Materialism: you equals your body. Death means non- existence.
'fearing about nonexistence is not only stupid but get in the way of enjoying life'
You and death are never present at the same time'
Life is like a night of drinking before the hangover that is death.which,inevitably,as it is ,you'll never actually experience.'
Zhuangzi:why would you fear about the inevitable?it's just a part of life circle
19. identity
Ship of Theseus
1.Identity:the relation that s thing bears only to itself
(what makes you unique defines your identity)
Two things are identical :they share an identical relationship
2.indiscernibility of identity( Wilhelm Leibniz)
If two things are identical ,
They must share all the same properties
Essential properties:
Core elements a thing needs to be the thing it is
Accidental properties:
Traits that could be taken away from the object without making it a different thing
"you can't step in the same river twice"
Everything is identical to itself because Everything is changing all the time
What identity means to persist over time?
26 language and meaning
Gottlab frege:
Reference:the reference of a word is the object or concept that it's meant to designate;
Sense:the sense of a word is the way in which the word ties us to the concept or the object.
Definition: traditionally understood as whatever meets the conditions for both necessity and sufficiency.（必要充分）
Ludwig wittgenstein:the original concept of definition dosen't work
We learn and know the meaning of the words by hearing the way other members of our linguistic community use them
Family resemblance: we recognize the thing through the things similar to them
Cluster concept: there is no one element that everything in the cluster has in common but they share something with some other members of the group.
Paradigm case: paradigm in the center and fringe(different people have different criterions to decide whether to include or exclude sth into the paradigm)
--'language is a living phenomenon,there's going to be change and variation'
--how to decide the meaning--wittgenstein'meaning is use'
Indicated premise: meaning is tied to a peticular linguistic community(differ with reigions and nations)
Beetles in box:'our mind is like boxes,no one else could see what is in it'
'language couldn't refer derectly to an internal state,it could only refer to aspects of it that's publically observed by other people'
Speaker meaning:what the speaker intends when using a word
Audience meaning: what the audience understands
--goal: speaker and audience meaning to match up
29-nonexisting objects& imaginary world
Alexus Meinong
Ontology
Absistence: nonexisting things
Subsistence: abstract concepts (triangle, numbers.. Do not exist in physical world
Existence: things exist in real world
--meinong's jungle
Aesthetic:
The domain in which we have a conversation is called a universe of discourse. Inside this universe assertions can be true or false.
Default universe is the real world
In conversation: when we talk about fiction, we are speaking in the specific universe of discourse, and the interlocutor knows that even if it isn't explicitly stated.--this allow us saying things that end up bring true even the truth does not track to the real world.
