Lecture 4 - Observation Flashcards
What is registration
subject registers concrete entity iff image of x is formed on retina of eyes long enough above retina’s sensitivity threshold and larger than retina’s resolving power
Vision/seeing/sensation
iff subject registers x and is aware of x (camera can register but not see)
What is observation
Observation = iff s registers x, is aware of x and pays close attention to x
Observation is never passive, and always has a purpose
Purposes of observation in science:
- Source of perceptual/observational knowledge (epistemic justification)
- Means of testing hypothesis, models, theories, basis for deriving regularities
- Guides refinement, adjustment and development of hypothesis, models and theories
What is conceptual vision/perception
iff s registers x, s is aware of x, s possesses a concept expressed by some predicate (F), s thinks that F(x) is true or false
Seeing that, is a propositional attitude
Mastery of a language is presupposed
What is conceptual truth
every observational belief necessarily expresses a concept, it is concept-infected. Without conception-infection, there is no conceptual seeing and no perceptual beliefs
Ambiguous and false vision
Ambiguous vision: conflicting perceptions and observational beliefs can be based on the same observation
False vision = false observational beliefs can be based on observation, we find out via other observations, knowing falsehood does not overrule what we observe
What do we observe & see?
- Phenomenologically, by saying that we are conscious of images on the retinas of our eyes, of re-presentations of present entities; we are aware of sensations caused by present entities, and thus we see present entities indirectly; and
- Realistically, by saying that we observe present entities directly, perhaps even as they are (although that is an additional metaphysical gloss), rather than indirectly, as in (A.I)
Classification of concepts in science
- Logical concepts
- Mathematical concepts
- Observational concepts
- Theoretical concepts
Criterion for observational concept
predicate is observational iff every human being under normal circumstances can (learn to) judge whether or not F applies to any given observable entity by performing only an observation, and without making any inferences, notably ones involving scientific knowledge.
Normal circumstances: psychologically, biologically, physically
Criterion for observability
Concrete entity x is observable iff for every human being S under normal circumstances: if S were in front of x in broad daylight with eyes wide open long enough, then S would see x
Sentence is observational / empirical iff:
- P is logically simple
- P is synthetic / not analytic
- P contains only observational predicates
- P is only about observable entities
Sentence p is observational evidence, iff:
- P is observational, true and actual (only about existing concrete observable entities)
Problem with observation reports in science
Observation reports in science hardly ever qualify as empirical evidence: they include theoretical concepts too, not only observational ones, if ever. Concepts like observational predicate and sentence are alien to scientists. Their observation reports are ‘infected by theory’, ‘charged with theory’.
Threats from theory-infected observation reports:
- Anti-logical-positivist threat: epistemic project of reducing scientific knowledge to sensory experiences via observation sentences collapses by theory infection
- Anti-test threat: two descriptions of same observations can be different, so still theory infected
- Blinders threat:
o Semantic: conceptual seeing is limited to concepts we happen to possess
o Saliency: our vocabulary guides our observations, marks what is salient (opvallend) - Expectation bias threat: we expect to see what we can see conceptually
- Circularity threat: qualitative observations hardly play a role in science, rather quantitative observations dominate: to connect measurements and data, infected with theoretical concepts, we need empirical biconditionals
Refutation anti-logical-positivist threat
rational reconstruction project is philosophical project
“We know real scientists do things differently, but our philosophical project is about creating an ideal, fully empirical model of science. What scientists actually do isn’t relevant to that goal.”
Refutation blinders threat:
- Semantic: we can always extend vocabulary if it doesn’t fit
- Salient: constant awareness is a scientific virtue
Refutation expectation bias threat
constant awareness is a scientific virtue
Circle of justification
theory is needed to justify empirical biconditionals, empirical biconditionals are needed to justify theory
Breaking out of circle;
- Fine-grained analysis: what is needed from theory as justification might be different part of theory than what is tested of theory
- Stipulate that empirical biconditionals are analytic truths (no explanation tho)
