242 Self and the Phenomenon of Life
b2726 Self and the Phenomenon of Life: A Biologist Examines Life from Molecules to Humanity “9x6”potentially create a storm in Asia. This is known as the “butterfly effect.”
Although theoretically the event is entailed in the mathematical equa-
tions, in practice the outcomes are highly unpredictable since no one
can be sure of the initial conditions at any given moment. The weather
bureau gives up forecasting for more than ten days because that would
require measurements to a degree of accuracy unattainable.
Another example of a deterministic condition that produces a sur-
prising outcome is the catastrophe theory, a mathematical model in
which a minor alteration in one variable at the critical point leads to an
abrupt, high magnitude change in another. In simple words, a continuous
action may produce an unexpected, sudden, discontinuous outcome.^7
The condition is said to be metastable. We see this when the addition of
a single grain of sand brings forth the collapse of a sand pile, or when
the passing of a casual skier precipitates an avalanche of an entire slope.
The bottom line is, although natural events are deterministic, in the
real world they are not always predictable, and frequently may come as
a surprise. Some philosophers take this as evidence that free will is just
an illusion.^8 In the subsequent sections I shall explain why this extreme
stance is not justified.
11.4 Navigating a Probabilistic World
We usually communicate about the future using such terms as “most
likely,” “more likely,” “less likely” or “highly unlikely.” Sometimes we are
more definite and we may say that this or that “will surely happen” or “will
surely not happen.” These are all semi-quantitative terms to characterize
a probabilistic world. The weather bureau tells us in a more scientific way
that there is, say, a 50% or an 80% chance of rain. In mathematics, prob-
ability is expressed as the ratio of the number of expected occurrences to
the total number of possible occurrences, and it ranges from 0 to 1.00,
with 0 as no chance and 1.00 as definite to occur. Most future events fall
within the two limits. Thus, an 80% chance of rain will mean a probability
of 0.80. As the saying goes, “never say never.” The future is open-ended,