Redefining Reality - The Intellectual Implications of Modern Science

The study of reality is what philosophers call metaphysics. Although
philosophers have traditionally discussed metaphysical questions
from a purely conceptual standpoint, advances in science have forced
a reevaluation of some traditional metaphysical views. In this lecture, we’ll
consider the example of the discovery of the germ theory of illness. The
discovery of harmful bacteria causing disease forced us to reassess how the
human body works and how it relates to the surrounding world. We’ll also
the work of historian and philosopher Thomas Kuhn, whose concept of a
within it.
René Descartes, known as the father of modern philosophy, began
his intellectual odyssey with this question: How do we know
that there is a reality outside our own minds? We each know that
we have experiences, and we can be sure of these experiences;
therefore, each of us can be sure that we exist. But how do we know
that the internal experiences we have correspond to objects outside
our minds?
You can see, smell, touch, and taste a loaf of bread, but those
experiences are in your mind, not out in the world. How, then, do
you know that there even is a world out there, and if there is, how do
you know that it resembles the world of your internal experience? If
all of your experiences are in your mind, how do you know that the
thing giving you the bread experiences is, in fact, bread?
Perhaps, Descartes considers, you are merely dreaming or
mind, creating a false universe that you wrongly believe is real.
Descartes ultimately rejects this hypothesis, in part because there
5