logic & critical thinking pt1

critical thinking

thinking based on criteria and standards that are vetted by tests and experience

socrates

first figure on record to devote his life to critical inquiry systematically

divine sign

socrates experienced a recurring inner voice (rationally grounded spiritual intuition)

the oracle of delphi

socrates’ friend chaerephon asked the oracle, “is anyone wiser than socrates?” oracle’s reply: “no one is wiser.” socrates was baffled so he began testing the oracle’s words.

truth

knowing things as they really are — reality as it actually exists, not as we imagine or wish it to be.

extrinsic good

good as a means to something else (ex: money = good because it buys things)

intrinsic good

good in itself, needing no further justification (ex: wisdom, love, happiness)

correspondence theory of truth

a statement or proposition is true if it matches reality, false if it doesn’t.

self examination

testing one’s own beliefs, actions, and values against rational and reliable criteria

two central socratic questions

“what exactly do you mean by that?” & “what evidence do you have for your claim?”

argument

one or more statements (premises) offered as evidence for another statement (the conclusion)

elenchus

the refutation stage of questioning, where contradictions are revealed

logically consistent

possible for both to be true

arete

excellence or virtue; fulfilling one’s essential function well

opposition to thirty tyrants

socrates refused to obey them even under threat of death. when ordered to arrest an innocent man, he refused because moral reason outweighed fear.

reason is privileged because…

1) it can criticize and correct itself. 2) it can test every belief, emotion, and impulse against evidence and truth.

socrates' charges

impiety & corrupting the youth

socrates’ counter

penalties

freedom’s price

to claim the right to your own moral judgments, you must accept the risk of misjudgment.

vagueness

uncertain application — we don’t know where the boundary lies. ex: “wealthy”

ambiguity

can be interpreted in two or more distinct ways. ex: “the reverend smith married my brother” (did he perform the ceremony, or is he the spouse?)

extensional definitions

explain a word by referring to all things it applies to. ex: the extension of city = seattle, los angeles, boston, etc

ostensive definition

pointing to examples. ex: “this is a circuit.”

enumerative definition

list examples. ex: “comedian means someone like colbert or stewart.”

operational definition

specify a test/operation for application. ex: “mineral A is harder than B if it can scratch B.”

paradigm case

cite one clear instance to explain. ex: “by moral principle, i mean a rule like ‘stealing is wrong.’”

intensional definitions

explain meaning by referring to the properties or characteristics something must have to fall under the term. ex: the intension of square = “a closed figure with four equal sides and four equal angles.”

necessary condition

must be true for the thing to apply (oxygen is necessary for fire)

sufficient condition

if true, guarantees the thing applies (jumping in a lake is sufficient to get wet)

lexical definition

standard, dictionary style definition (e.g., chair = a seat for one person with four legs and a back)

stipulative definition

newly assigned meaning for a term in a specific context (e.g., flipper = “someone who flips criticism back”)

precising definition

refines a vague term to make it more exact (e.g., defining house for legislation as “a permanent dwelling with at least one door, floor, and roof”)

theoretical definition

defines using a scientific or conceptual theory (e.g., light = electromagnetic radiation traveling at a constant speed)

persuasive definition

emotionally charged definition meant to sway opinion (e.g., defining capitalism as “a system where the strong crush the weak”)

synonymous definition

explains by using a synonym (e.g., freedom = liberty)

analytic definition

breaks a concept into its component parts (e.g., bachelor = unmarried adult male)

rational criterion of morality

a kind of philosophical moral compass used to guide judgment between right and wrong

evidence

the reason(s) to believe a claim is true

statement (proposition)

a sentence that asserts something true or false (declarative). ex: carbon is an element

premise

a statement providing evidence for a conclusion

conclusion

the statement being supported

conclusion indicators

therefore, so, hence, it follows that, thus, consequently, accordingly, as a result, in conclusion, this entails that, we may conclude that

premise indicators

because, since, for one thing, for the reason that, inasmuch as, may be inferred from, as shown by, owing to, given that, due to the fact that, assuming that, as indicated by

deductive argument

aim is to prove the conclusion with complete certainty; if all premises are true, the conclusion must be true.

inductive argument

aim is to show that the conclusion is probable or likely true, not certain

deductive indicators

must, necessarily, certainly, for sure, definitely, absolutely

inductive indicators

probably, likely, it is reasonable to conclude

validity

perfect logical structure; truth of premises is a separate issue

valid argument

conclusion must be true if premises are true

invalid argument

conclusion does not necessarily follow from premises

strong argument

if premises are true, conclusion is probably true (over 50% likely)

weak argument

if premises are true, conclusion is not probably true

strength

how well the premises make the conclusion likely

principle of charity

treat opponents’ arguments fairly and in their strongest form; focus on reasoning, not personality

principal of faithfulness

represent others’ views accurately and completely

alethic relativism

claims that if you believe something is true, it’s true for you. there’s no objective truth; only truth relative to each person. this view denies any objective basis for evaluating beliefs. it results in critical thinking being impossible, since no claim can be judged mistaken.

moral relativism

claims that if you believe something is right/good, it’s right for you. there’s no objective morality; just personal or cultural opinion. blocks moral reasoning and accountability.

skepticism

claims that knowledge is impossible. if true, we can never know anything for certain.

sophists

traveling Greek teachers who claimed to teach communication and critical thinking, but focused more on winning arguments than seeking truth.

protagoras

sophist and a main opponent of socrates, known for teaching that truth and morality are relative.

global alethic relativism

all truth is relative (about every subject)

religious alethic relativism

only religious claims are relative; scientific ones are objective

aesthetic relativism

only beauty or art judgments are relative

individual alethic relativism

truth is relative to the individual

cultural alethic relativism

truth is relative to one’s culture

the infallibility argument

if alethic relativism is true → everyone is infallible (never mistaken about anything). this is clearly absurd bc people have been wrong before. therefore, alethic relativism is false.

the critical thinking argument

if everyone is infallible → critical thinking is impossible, since we’d never need to test our beliefs. but self correction and improvement rely on the possibility of being mistaken. therefore, alethic relativism is false.

global skepticism

all knowledge is impossible

limited skepticism

knowledge is possible in some areas but not others

religious skepticism

denies religious knowledge

aesthetic skepticism

denies knowledge about beauty

epistemology

study of knowledge

practical knowledge

knowing how. (e.g., knowing how to ride a bike)

acquaintance knowledge

knowing who. (e.g., knowing a person)

propositional knowledge

knowing that/knowing a fact (e.g., the earth is round) (main focus of philosophy)

the jtb theory of knowledge

S knows that P if and only if: Belief condition: S believes P is true. Truth condition: P is actually true. Justification condition: S has adequate justification for believing P. all three are jointly sufficient and individually necessary for real knowledge.

epistemic justification

a belief is justified if we have adequate reason to believe it is true, i.e., a reason solidly connecting it to reality.

pragmatic justification

defending a claim not because it’s proven true, but because it’s useful or works well in practice, e.g. believing your team will win because it boosts confidence

belief condition objection

“i know it, but don’t believe it.” → dismissed; belief is necessary.

truth condition objection

“people in the middle ages knew the sun revolved around the earth.” → false; they believed it, but knowledge requires truth.

justification objection

“lucky guesses can be right.” → not real knowledge without a reason linking it to reality.

the edifice of belief

beliefs often support one another

foundationalism

all beliefs are ultimately justified by basic (foundational) beliefs. these basic beliefs are self evident, not based on other beliefs + justify themselves.

noetic structure

the intellectual structure of all beliefs

infinite regression theory

rejects basic beliefs and says justification always depends on something else. (problem: no belief would ever be fully justified.)

coherentism

emphasizes balance and mutual support; beliefs change together as new evidence comes in

a posteriori / sense experience (empiricism)

knowledge gained through observation — what we see, hear, touch, taste, or smell

touchstone

test or standard for truth

the “power of expectancy”

perception shaped by belief or anticipation

a priori knowledge (rationalism)

knowledge justified through reason alone, without sense data. e.g., “nothing is both red and green all over at the same time.”

logical error

your reasoning process is flawed (ex: wrongly “proving” 12 is prime)

conceptual confusion

you misunderstand the meaning of a concept

shared rational insight

appeal to arguments everyone can follow through reason

concept clarification

refine vague or ambiguous concepts to reduce misunderstanding

cognitive bias

a psychological impulse that causes someone to jump to a conclusion or make a decision before having enough info to reason properly

confirmation bias

the tendency to seek and notice evidence that confirms what we already believe, while ignoring or downplaying disconfirming evidence

selective attention bias

the tendency to notice only information that supports one’s beliefs, ignoring what contradicts them

belief bias

the tendency to judge an argument based on whether we agree with its conclusion rather than evaluating its actual logic or evidence

bandwagon bias

adopting beliefs simply because many others hold them or because they’re shared by a group we belong to

ethnocentrism

the tendency to view one’s own group as superior and others as inferior