Karl Popper; Science; and Pseudoscience: Crash Course Philosophy #8 Video Lecture | What is Philosophy - Science or Religion? - Self Help Learning

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Imagine being alive when Albert Einstein was
developing his theories of relativity.
Or witnessing the birth of psychology, as Sigmund Freud and psychoanalysis took over the scientific mainstream.
The early 1900s was an amazing time for Western
science.
There was another figure on the intellectual
scene when these great minds were at work.
Young philosopher Karl Popper was born in
Austria -- Freud’s home turf -- but built
his career in Britain, giving serious consideration
to the new ways that these and other scientists
of the time were thinking about the world.
And after looking at different methods that
people like Einstein and Freud were using,
Popper came to understand that not all scientific
achievement was created equal.
He ended up making an important distinction,
between science … and what he called pseudo-science.
And in the process of doing this, he taught
us volumes about the nature of knowledge itself,
and how we can best test it, and challenge
it, to bring us closer to the truth.
[Theme Music]
Emerging at roughly the same point in history,
Freud and Einstein both made predictions that
they hoped would help us better understand
our world.
Freud, concerned with the individual psyche,
predicted that our childhood experiences would
have a heavy bearing on who we grew up to
be.
Meanwhile, Einstein waited patiently for a
solar eclipse that could disprove his entire
general theory of relativity, depending on what it would reveal about how light travels through space.
And then there was Karl Popper, born in 1902,
who grew up to observe these predictions with
keen interest. As a young scholar, he learned
about the psychoanalytic theories of Freud,
and attended lectures given by Einstein himself
about the rules of the universe.
And he noticed that these great thinkers used
different methods.
For example, Popper observed that Freud was
able to make just about any data point work
in service of his theory. Freud could explain
a person’s intimacy issues both in terms
of not being hugged enough as a child, or
in terms of having been hugged too much. Meanwhile,
almost any behavior on the part of a female
could be explained in terms of penis envy.
Evidence to support Freud’s theories seemed
to be everywhere!
But Popper saw that Einstein was making a
different type of prediction.
Instead of looking backward, and using past
data to “predict” the present, he was
looking ahead, and predicting future states
of affairs. Einstein’s theory was truly
risky, Popper realized. Because, if the future
didn’t match his predictions, then his theory
would be conclusively disproven. If the results
of the solar eclipse in 1919 had been different,
general relativity would have been finished.
Freud, on the other hand, could always just
read the past differently, so as to maintain
some kind of confirmation of his theory.
Suddenly, Popper understood the difference
between the science that Einstein was doing,
and what Freud was doing, which Popper rather
snootily referred to as pseudo-science.
Now, whether psychology today is considered
a hard science or a social science or some
other kind might be debatable. But you won’t
find many mainstream thinkers who consider
it pseudoscience. But still, nearly a hundred
years ago, when Popper was reaching these
conclusions, no modern philosopher had really
characterized what “science” truly meant
-- and what the implications were for the
pursuit of knowledge.
The traditional understanding of the scientific
method, going all the way back to the ancient
Greeks, relied on the belief that, to look
at the world with a scientific eye is to observe
with no preconceived notions.
You simply look, see what you see, and then
develop hypotheses based on those observations.
So, you look at a swan, and you notice it’s
white. You look at another swan; it’s white too.
You look at enough white swans, and eventually
you form the hypothesis that all swans are white.
This is what Freud said he was doing: Observing
relationships -- but instead of it being between
the relationship swans and colors, it was between particular human phenomena and human behavior.
But Popper argued that everyone has preconceived
notions of some kind. We all start out with
a hunch, whether we admit it or not.
After all, what you decide to observe is determined
by what you already care about enough to observe
in the first place and the fact that you care
about it so much also means that you already
have some beliefs about it.
So, what does that tell us about Freud?
Popper became convinced that methods like his that only served to confirm beliefs were pseudo-science.
And they could be used
to prove anything.
Consider the existence of Santa Claus. If
I try to find evidence of Santa’s existence,
I’m going to find it, easily. The world
is filthy with evidence of Santa Claus! There
are presents under the tree on Christmas morning.
There’s the guy at the mall. And then there
are all those songs, and stories, and tv shows, and movies – they combine to confirm your belief in Santa.
But Popper would argue that it’s only by seeking to disprove Santa’s existence that you can demonstrate his unreality.
So the question is, when we begin to test a theory, are we looking to confirm it, or disconfirm it?
This is the key point, for Popper – science
disconfirms, while pseudoscience confirms.
He elaborated on this insight by establishing a series of distinct conclusions about science and knowledge.
First, he said, it’s easy to find confirmation
of a theory if you’re looking for it.
Remember the presents under the tree? If
you’re looking for proof that Santa exists, you’re not
likely to keep searching for contradictory
evidence after that.
Second, confirmation should only count if
it comes from risky predictions – ones that
could actually destroy your theory. Because,
Popper observed that every good scientific
theory is prohibitive – it rules things
out.
This might sound strange, because no one wants
to be wrong, but Popper says that every false
belief we discover is actually good, because that gets us that much closer to believing only true things.
Next, Popper argued that the only genuine test of a theory is one that’s attempting to falsify it.
So, if you were to test for Santa’s reality, your method would require you to try to prove that he doesn’t exist,
rather than proving that he does. So, you stay up all night, waiting to catch him delivering his presents.
This is risky, because if the person who actually shows up to put presents under the tree is your Dad,
then you’ve destroyed the Santa hypothesis.
On a very similar note, Popper also pointed
out that irrefutable theories are not scientific.
If it can’t be tested, then your theory
doesn’t have much value.
Like, you can only confirm that Santa is real
by doing everything in your power to prove
that he’s imaginary, and then failing to
do so. So you need to be tugging on Santa
beards at the mall. You need to investigate
reports of Santa sightings, and other weirdoes
caught breaking into peoples’ houses through
their chimneys. If you want to be able to
really trust in your belief in Santa, in a
genuinely scientific way, you need to put
your belief to the test, in every way you
can imagine.
This is where Popper says that you have earned
the right to call a theory scientific.
And finally, once you’ve disproven your theory, Popper said, you need to be willing to give it up.
I mean, you can still cling to the Santa myth, even after catching your Dad putting gifts under the tree,
by accepting his lie that Santa had dropped the gifts off earlier, and that he was just “helping.”
But, if you’re a scientist, you’re gonna
have to be willing to let your beliefs go.
Accept the evidence. Move on.
And this is the modern scientific thinking that we
accept today: Testable, refutable, falsifiable.
You don’t seek to prove scientific hypotheses
right, you only prove them wrong.
A lot of this might seem so obvious that maybe
you’re wonder why we’re talking about it.
But that’s how right Popper was – he
was one of those rare philosophers who actually
managed to hit on an idea so right that we don’t
even really argue about it anymore.
So, it sounds like I’ve been talking mainly
about science all this time. But Popper and
his insights actually tell us a lot about
knowledge, in the philosophical sense.
For Popper, knowledge was about probability
and contingency. We are justified in believing
whatever seems most probable given our current
data. And we should always be willing to revise
our beliefs in the light of new evidence. In other words, our belief should be contingent on the data themselves.
This wouldn’t have satisfied Descartes,
who was always concerned about certainty.
But Popper never thought that certainty was
possible in the first place. If anything,
he thought being certain of something
causes you to close your mind, and that’s
not what we want. Always remaining open to
the idea that your current beliefs might be
wrong is the best way to get ever closer to
truth.
So where does this leave us?
Remember, we started out trying to prove that
we know the things we thought we knew. But
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. Otherwise, we’re all just
believing whatever we want, with no grounds
for adjudicating between beliefs.
You should keep that in mind, because that’s
the name of the game for the rest of this course.
You only get to believe the things
you have reasons for, and we’re going to
start with the area that is hardest for most
people – God. Hope to see you there.
Today you learned about Karl Popper, and his
insights into science, pseudoscience, and
knowledge -- which might best be summarized as science disconfirms, while pseudoscience confirms.
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