Updated: 21 January 2000
Science - observation and
OK - but cooking too involves observation and principles
Bacon Novum Organum
“Idols and false notions … are now in possession of the human
understanding, and have taken deep root therein, … truth can hardly find entrance
“The conclusions of human reason as ordinarily applied in matter of
nature, I call for the sake of distinctions Anticipations
of Nature (as a thing rash or premature). That reason which is elicited
from facts by a just and methodical process I call Interpretation of Nature.”
“One method of delivery alone remains to us; which is simply this: we
must lead men to the particulars themselves, and their series and order; while
men on their side must force themselves for awhile to lay their notions by and
begin to familiarise themselves with facts”
“… the winning of assent, indeed, anticipations are far more powerful
than interpretations; because being collected from a few instances, and those
for the most part of familiar occurrence, they straightway touch the
understanding and fill the imagination; whereas interpretations on the other
hand, being gathered here and there from various and widely dispersed facts,
cannot suddenly strike the understanding; and therefore they must needs, in
respect of the opinions of the time, seem harsh and out of tune;…”
Here a white swan, there a white swan …
Ergo : All swans are white
“a scientist should make a
large number of careful observations, and then obtain predictions and
generalizations by the process of inductive inference from these observations”
Gillies Philosophy of Science in
the Twentieth Century (Blackwell 1993)
a method of discovery
a method of justification
further observation –
Not the entire story
Inference to the best explanation - posit hypothesis or theory on the grounds that it provides best
Typical of modern science
we are puzzled about what we
observe, scientist tells a story written
in a new vocabulary
argues for the story on the
basis of its explanatory power
realist vs instrumentalist
construal of the story
Inductivism - a role to play ? a starting point ?
HUMEAN EMPIRICISM - experience
as source of all knowledge and of all meaning
PRINCIPLE OF SIGNIFIGANCE
“All ideas are derived from
rule out verbiage
some words have meaning by standing for a kind of experience - “red”
all other words have meaning in virtue of being definable in terms of
end of metaphysics
trouble for physics ? “absolute
but see Galen Strawson for contrary
we know the contents of our
will today’s bread nourish?
uniformity of nature ?
induction vs deduction
induction by simple
inference to the best
Hume - not even sure its bread
logical thesis : bemusing condition
psychological thesis : can’t help it
contrast with Bacon
Vienna 1920 - 1936
Inspired by Hume and Einstein and the “scientific revolutions”
Neurath Schlick Carnap Feigl Reichenbach (Godel, Quine, Wittgenstein,
Popper, Ayer, Nagel)
Principle of signifigance
Hume - problem of words like
Verifiability Principle - a
sentence a has meaning if and only if
it is verifiable
meaning given by verifiability conditions
Analytic - OK
Mathematics - definitions
the new physics
Einstein - STR 1905
1. “A simultaneous with B”
inspired by Hume ???
“Einstein told the physicists (and philosophers): you must first say
what you mean by simultaneity, and
this you can only do by showing how the
statement ‘two events are simultaneous’ is verified. But in so doing you have
then also established the meaning fully and without
remainder. What is true of the simultaneity concept holds good of every
other; every statement has a meaning only insofar as it can be verified; it
only signifies what is verified and
absolutely nothing beyond this. Were
someone to maintain that it contains more, he would have to be able to say what
this more is, and for this he must again say what in the world would be
different if he was wrong; but he can say nothing of the kind, for by previous
assumption all observable differences have already been utilized in the
2. Kant - a priori arguments
to determine structure of space and time
philosophy to emulate science
Reichenbach The Rise of Scientific Philosophy
Newton - a bad guy
Contrast with Bacon
positivists were not
context of discovery
context of justification
2. justification of induction
Positivists worried a lot
“vindication” of induction
“problem to be solved”
Construction of Science
“If we suppose that I at once take note of every observation – and now
start out from thence to construct science, I would have before me genuine
‘protocol propositions’, standing temporally at the outset of knowledge. From
them the remaining propositions of science would gradually be evolved through
the process which we call ‘induction’, and which consists simply in the fact
that, stimulated or incited by the protocol propositions, I tentatively set up
general propositions (‘hypotheses’), from which these first propositions, along
with innumerable others, logically follow. Now if these others say the same as later observation-statements,
obtained under quite specific circumstances that have to be exactly stated in advance, then the hypotheses
continue to rank as confirmed so long as observation-statements do not crop up
which are in contradiction to the propositions derived from the hypotheses, and
hence to the hypotheses themselves. So long as this does not happen, we believe
ourselves to have guessed correctly at a law of nature. Induction is therefore
nothing else but a methodically guided guessing, a psychological, biological
process whose execution has certainly nothing to do with ‘logic’.”
algorithmic conception of scientific method
mathematical logic - algorithm checking proofs
inductive logic - algorithm for checking support provided to a given
hypothesis by a given body of evidence
Nagel in 1953
“… we do not possess at
present a generally accepted schema for weighing the evidence for any
arbitrarily given hypothesis so that the logical worth of alternative
conclusions relative to the evidence available for each can be compared.”
POSITIVISTIC PICTURE OF SCIENCE
1. Observational vs
O - meaning
T - meaning via O
i. pure T- postulates (eg F=ma)
ii. mixed - correspondence
x has mass t if and
only x placed in S gives reading of t
3. discovery vs justification
4. confirmation - successful
derived predictions support
5. explanation by deduction
7. philosophy - analysis of
realism vs instrumentalism
what about the
principle itself ?
accepts Hume’s logical
rejects Hume’s pyschological
induction by simple enumeration
inference to the best explanation
1 Sa & Wa, Sb & Wb, ...
2 \ All Ss are W.
Premises provide no support
3 Sc & not Wc
4 \ It is false that all Ss are W.
Method : bold conjectures and refutation.
1. no justification for
2. part of our nature to use
1. no justification for
2. not used (at least by “great” scientists such as Newton)
Premise(s) entail the
Good Inductive Arguments
Premise(s) support but do
not entail the conclusion.
For Popper only deduction is legitimate:
“only the falsity of a theory can be inferred from empirical evidence
and this inference is purely a deductive one”
“without waiting for premises we jump to conclusions. These may have to be discarded later, should
observation show that they are wrong” (C&R)
Premises do not even raise the probability of the conclusion. Probability of all empirical universal laws
Lots of content
The more the risk, the
greater the content
All swans are white or pink
or black or green.
All swans are white.
No induction from the data.
See Medawar’s The Limits of Science
scientist wants to refute
derives prediction, conducts
If refuted, start again. If not refuted, it is corroborated.
Corroboration is not inductive support
Passing a test provides no positive evidence.
Popper’s aim -
Criterion of demarcation
A theory is scientific if
and only if it is falsifiable.
Einstein vs Adler, Freud, Marx
1919 Eddington’s test of General Relativity
Contrast with Vienna Circle
- nothing to do with meaning
- to explicate cognitive
meaning via verification is to use induction.
Realism - aim of science is truth
truth - correspondence
Rationalist - critical approach
search for refutations
learn from mistakes
all we learn is that
something is false
Really rational ?
Finite number of theories ?
T2 more ver. than T1
contains more truth but not more falsity
contains same truth but less falsity
Theory is a set of sentences
Thesis of Verisimilitude TV
Animal Farm Move - progress
What does verisimilitude really mean?
Miller: all false theories have same degree of verisimilitude.
Good project for graduate school.
How could we show that our theories are increasing in verisimilitude?
1. Induction by simple enumeration ?
only with a little help from
an omniscient being
2. Relative success rates ?
3. Inference to the best explanation
Galileo - mountains on
Einstein - atoms produce
Best explanation of the fact that theories improve is predictive power?
Theories have greater verisimilitude.
“...it would be a highly improbable coincidence if a theory like
Einstein’s could correctly predict very precise measurements not predicted by
its predecessors unless there is ‘some truth’ in it. ... it is probable that the theory has a higher degree of
verismilitude than those of its competitors which led to predictions that were less
... “there may be a ‘whiff’ of
If induction allowed here, why not elsewhere?
If not here Popper fails to fit rational model
And if elsewhere what is unique in Popper?
Role of experiments in philosophy.
Quine and meaning
Nietsche and truth
1. Why assume a falsified
theory remains falsified?
2. Why rely on a theory if you
have no positive evidence for it?
3. Probability judgments are
4. “All theories are born
Never abandon except for a
some dogmatism allowed if
scientist declares in advance conditions for rejection.
5. Status of observation
Popper: matter of convention
6. No tests in isolation.