philosophy
view markdownNotes on philosophy relevant to explanation (particularly in science)
basics
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try to understand what principles underly all phenomena
- Machine Learning and the Future of Realism (hooker & hooker, 2017)
- lack of interpretability in DNNs is part of what makes them powerful
- naked predictions - numbers with no real interpretation
- more central to science than modelling?
- no theory needed? (Breiman 2001)
- old school: realist studied neuroscience (Wundt), anti-realist just stimuli/response patterns (Skinner), now neither
- interpretability properties
- simplicity - too complex
- risk - too complex
- efficiency - basically generalizability
- unification - answers ontology - the nature of being
- realism in a partially accessible world
- overall, they believe there is inherent value of ontological description
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Explainable Artificial Intelligence and Machine Learning: A reality rooted perspective (Emmert-Streib et al. 2020)
- explainable AI is not a new field but has been already recognized and discussed for expert systems in the 1980s
- in some cases, such as simple physics, we can hope to get a theory - however, when the underlying process is complicated, interpretation can’t hope to simplify it
- in other cases, we might hope just for a description
- explainable AI is not a new field but has been already recognized and discussed for expert systems in the 1980s
scientific explanation (SEP)
- distinction between scientific explanation and non-scientific explanation (although can put things on a spectrum)
- distinction between explanations and accounts which are “merely descriptive”
- these theories focus only on explanations of why things happen
- concepts: explanation, description, causation
some overarching examples - what causes what?
- do birth pills stop pregnancy (both for men/women)?
- sun, flagpole, shadow
- barometer, air pressure, storm
- collision of pool balls
- supply/demand curves in economics
- gas law $PV=nRT$
DN model = Deductive-Nomological Model
- by Popper, Hempel, Oppenheim (popper 1935, hempel 1942)
- explanation has 2 constituents
- explanandum - sentence describing phemonenon to be explained
- explanans - class of sentences used to account for the phenomenon
- deductive
- explanans must be true
- explanandum must be a logical consequence of the explanans
- nomological = “lawful”
- explanans must contain a “law of nature”
- the law of nature must be essential to deriving the explanans
- still hard to decide exactly what is a law - should be exceptionless generalizations describing regularities
- can have probabilistic laws as well (e.g. prob of recovering after taking penicillin is high)
- why this framework
- by framing terms of laws and cricumstances, the explanation shows that the phenomenon was to be expected and helps us understand why it occured
- sometimes, an explanation-sketch uses words like cause, that can be reframed more precisely in the DN model
- counterexamples
- assymetry (e.g. shadow length, flagpole height, sun angle) - derive shadow length seems explanatory, but not deriving flapole height
- irrelevant details (e.g. being a man + taking birth control pills explains why you don’t get pregnant)
- feels like their is something missing about “causality”, but this is difficult to pin down - suggests DN model states necessary but not sufficient conditions
- features of an explanation must be recognized / used by users of an explanation
statistical relevance - wesley salmon
- starts with (salmon, 1971)
- given some class or population A, an attribute C will be statistically relevant to another attribute B iff $P(B∣A,C) \neq P(B∣A)$
- find a set of attributes which divide the target into a homogenous partition = even if we split the cells further, they keep the same probability
- like in causal inference, assume no missing variables
- then, the explanation for a new target x gives the cells, the prob. for each of the cells, and which cell x belongs to
- find a set of attributes which divide the target into a homogenous partition = even if we split the cells further, they keep the same probability
- this method is almost information-theoretic - same explanans equally explains the same model with inverted probabilies
- ex. (Salmon, 1971) atmospheric pressure, barometer, and storm - barometer is explanatory but not causal
causal mechanical models
- starts with (salmon, 1984)
- elements
- causal process - leaves marks on the world which persist spatiotemporally (these marks hint at counterfactuals)
- contrasts with a pseudoprocess, like a shadow
- causal interaction - interaction of such processes, e.g. a car crash
- causal process - leaves marks on the world which persist spatiotemporally (these marks hint at counterfactuals)
- explanation consists of 2 parts which both track causal process + interactions
- etiological - leading up to event
- constitutive parts - during event
- issues: hard to distinguish between explanatory causes (e.g. for a pool ball collision, mass + velocity) vs other so-called causal processes (e.g. chalk mark on ball)
- tends towards overly complex physical descriptions - e.g. for gas law track all particles rather than something global like pressure
unificationist models
- important attempts include friedman (1974) and kitcher (1989)
- seeks a unified account of a range of different phenomena
- best explanations explains most phenomena with as few + as stringent arguments possible
- potential issues
- causal asymmetries - equally likely to say planets in future cause motion now then planets now cause motion in the future - this is honestly probably fine
- doesn’t easily admit laws at different graunlarities
pragmatic = contextual explanation models
- scriven (1962), bromberger (1966), van Fraassen (1980), achinstein (1983)
- takes audience into account
- others have been after characterizing a single “true” explanation and the role of the audience was minimized
- “pragmatic” here means not just useful but also explicitly considering psychology + context
- “Causal–explanatory pluralism” (lombrozo 2010 [PDF]) - subjects prefer explanations that appeal to relationships that are relatively stable (in the sense of continuing to hold across changing circumstances)
- constructive empiricism (Bas van Fraasen)
- just want theories that are “empirically adequate”
- explanations are answers to questions - usually why? questions
- explanations pick something from a set and tell why it is not any of the other things in the set (the set is given from context)
- explanation is …“a t three-term relation between theory, fact, and context”
- asymmetries coem of rom context
- main criticism: this theory is too flexible, ironically it might be too flexible to be meaningfully (practically) useful
- however, it is possible that this is the most flexible framework that is still accurate
- want context to come in for as few steps as possible during an explanation - maybe we don’t need to analyze human psych
- somewhat circular - if this is true, then how can we resolve ambiguities?
open areas
- understand casuality
- more focus on whethery expalanations capture our intuitive judgements and more on the issue of why the info they convey is valuable + relates to our goals
- to what extent does a single model work across sciences (e.g. biologists claim to be interested in mechanisms whereas physicists in laws)
philosophy of science
thomas kuhn
- science enjoys periods of stable growth punctuated by revisionary revolutions
- the development of science is driven, in normal periods of science, by adherence to what Kuhn called a ‘paradigm’
- The functions of a paradigm are to supply puzzles for scientists to solve and to provide the tools for their solution
- A crisis in science arises when confidence is lost in the ability of the paradigm to solve particularly worrying puzzles called ‘anomalies’
- scientific revolutions involve a revision to existing scientific belief or practice
- the development of science is driven, in normal periods of science, by adherence to what Kuhn called a ‘paradigm’
- ‘incommensurability thesis’ - theories from differing periods suffer from certain deep kinds of failure of comparability
- controversial - goes against the idea that science constantly builds
the story of philosophy
book by will durant
- states his own view that philosophy should focus on ethics rather the epistemiology (i.e. how we know what we know)
- every science begins as philosophy and ends as art
- some definitions of philosophy
- pursuit of fundamental laws
- quest of unity
- plato
- socrates, plato’s teacher pursued stricter definitions and was put to death
- plato writes the Republic - fictitional dialogue w/ socrates as the protagonist
- argues that democracy failes because people are greedy
- advocates for an absolute meritocracy with 3 classes
- ruling class should live like communists, decent state salary, disallowed from excess
- soldiers / auxiliaries
- general population
- requires equality of education
- requires religion to placated the non-ruling majority
- excess is regulated
- justice = having and doing what is one’s own
- each shall receive equivalent to what he produces + perform function for which he is best fit
- juxtapositions
- jesus: kindness to the weak
- nietzsche: bravery of the strong
- plato: effective harmony of the whole
- only 3 things: truth, beauty, + justice
- aristotle
- starts systematic science, library science, and logic
- advocates for uinversals as individuals (e.g. a man, not man like Plat argues for)
- this is more grounded in reality
- theology: God moves the work like force, but does little else
- science: infinitesimal distinctions - boundaries between plant/animal categories are blurry
- form: man, matter: child = possibility of form
- politics: ideally a monarchy / aristocracy but more realistically would be constitutional gov. (people determine needs, leaders determine how to meet them)
- restrictions on pop.
- believes in slavery / female inferiority
- francis bacon
- lived in 1500s/1600s in England
- father of the scientific method
- objective and realistic
- in contrast to descartes = subjctive/idealistic
- “I think therefore I am”
- bacon embraces epicureanism - don’t want anything
- scors knowledge that doesn’t lead to action
- science = organization of knowledge
- philosophy = organization of science
- doubt all assumptions
- spinoza
- baroch de espinoza
- jew who was excommunicated for anti-religious writing
- no distinction between body and mind
- no free will - only desires that guide everything
- beginnings of doubting rationalism
- voltaire
- frenchman who was exiled
- seeks history of ideas, beginning with The Essay on Morals
- Candide - short story, denouncing optimism for pragmatism
- real philosophy begins with Philosophic dictionary
- strongly against superstition
- wrote simple, accessible pamphlets
- in his later years, turns to focus on the pursuit of usefulness rather than truth
- contrasts with younger Roussea, who wanted more action, instinct, social contract
- kant: mind has prior beliefes
- what makes a math law better than some other thing? kant says a priori beliefs…interestingly those beliefs were from evolution in the first place
- mind is not blank slate: mind filters in what we perceive a priori in contrast to growing popular belief that everything comes from perception
- understanding can never go beyond the limits of sensibility
- certain things in science/religion etc. can never be known, just interpreted
- time and space are not realities but just our interpretations
- lots of connections to priors in modern AI research
- morals come from an innate sense
- somewhat pro-religion but not fully, still still faced persecution in Prussia
- “Have strongly-held values, and malleable opinions”. - Francois Chollet tweet
- schopenhauer
- everything is will: continuing trend from espinoza + kant against rationalism
- pessimist: even in Utopia, ennui sets in
- objects of science is universal that contains many particulars while object of art is particular than contains a universal – this requires more genius
- herbert spencer
- evolution as a guiding philosophy of everything
- darwin published Origin of Species in 1859, when spencer was 40
- spencer is thus more lamarckian
- greatest contributions were to sociology: carefully curates data for sociology analysis
- resulting philosophy is conservative, laissez-fare, anti-regulation
- friedrich nietzsche
- evolution as morality: favors the strong
- germans have 2 words for good / bad - one is closer to strong, the other to kind
- everything is due to an underlying will for power
- evolution towards “the superman”
- bertrand russel
- starts with symbolic reasoning
- after WWI, shifts tow grounded philosophy in pacifism, communism
stability
- Foundationalism - where the chain of justifications eventually relies on basic beliefs or axioms that are left unproven
- Plato’s Republic
- the stability of belief: how rational belief coheres with probability (leitgeb, 2017) - introduction
- To Explain or to Predict? (Shmueli, 2010)
- explanatory modeling as the use of statistical models for testing causal explanations
- many philosophies view explanation and prediction as distinct (but not incompatible)