Staying relevant and meaningful requires constant probing and ceaseless updating of your worldview.

1. Making Sense
of a Fast Changing
Unpredictable World

2. Heraclitus
• Πάντα ῥεῖ
• Panta Rhei
• Everything Flows

3. Hōjōki
The current of the flowing
river does not cease, and
yet the water is not the
same water as before.
The foam that floats on
stagnant pools, now
vanishing, now forming,
never stays the same for
long. So, too, it is with the
people and dwellings of
the world.

4. 三十年河东，三十年河西
• The Chinese saying "sometimes the river flows
East and sometimes the river flows West" is "三
十年河东，三十年河西".
• It means things change with time and the
situation, someone can not be successful forever
and someone will not be hapless all the time, just
like an English saying "Every dog will have his
day".
• It is not only a metaphor pertaining to one's life,
but also can be used to describe the changes in
larger fields.

5. Zeitgeist
• Constant probing and
ceaseless updating of
your worldview

6. Philip Tetlock
• American political
scientist and
psychologist
• Fox and Hedgehog
differences

7. Sir Isaiah Berlin
• British Philosopher
• There are two kinds of
thinkers in the world:
• Hedgehogs: who know
on big thing
• Foxes: who dart from
idea to idea.

8. Reference
• fragment attributed to
the ancient Greek poet
Archilochus: πόλλ' οἶδ'
ἀλώπηξ, ἀλλ' ἐχῖνος ἓν
μέγα
• "the fox knows many
things, but the
hedgehog knows one
big thing".

9. Comparison Examples
Hedgehogs
• Plato
• Lucretius
• Pascal
• Hegel
• Dostoevsky
• Nietzsche
• Ibsen
• Proust
Foxes
• Herodotus
• Aristotle
• Montaigne
• Erasmus
• Moliere
• Goethe
• Pushkin
• Balzac
• Joyce

10. Accuracy in Forecasting
Tetlock draws heavily on
this distinction in his
exploration of the
accuracy of experts and
forecasters in various
fields
– politics
– International affairs
– Economics
in his 2005 book Expert
Political Judgment: How
Good Is It? How Can We
Know?

11. Studies
• Interviewed hundreds
of experts and asked
them to make
prediction about the
short-term future
• The next five years

12. Low Scorers Look Like Hedgehogs
• Thinkers who know ‘one
big thing’ aggressively
extend the explanatory
reach of that one big
thing into new domains.
• When you have a
hammer, everything
looks like a nail

13. High Scorers: Foxes
• Skeptical of easy historical
analogy
• More probabilistic in the
their thinking
• Comfortable updating
their models
• The more wide ranging
their curiosity, the more
accurate they tended to
be
• Fast updating Foxes

14. Limits of Knowledge
Cognitive Bias
We normally expect
knowledge to promote
accuracy, so if it was
surprising to discover
how quickly we reached a
point of diminishing
returns, it should be
downright disturbing to
discover that knowledge
handicaps so large a
fraction of forecasters.