THE NATURE OF
HISTORICAL SCIENCE
What is the scientific
method?
Although
different fields of scientific study have unique ways of approaching their
subject, there are some basic elements that characterize the scientific
methodologies.
1)
Observations are made of the natural world, whether directly or through the use
of instruments.
2)
Perceived patterns and regularities in these observations become the basis for
proposing a hypothesis to explain them.
3)
A new set of observations not yet made is predicted from the hypothesis.
4)
The hypothesis can then be tested against these new observations, and modified
or rejected if necessary.
Although
hypotheses can be rejected by the methodology of science, they cannot be
positively proven in the sense of a mathematical or logical proof. The construction of scientific
hypotheses is influenced by philosophical, religious and cultural assumptions
of which the investigator may be unaware.
However, those hypotheses are subject to test, and will not become
widely held by the scientific community unless those predictions are
fruitful. The more a hypothesis,
or set of related hypotheses, effectively explains our observations of the
natural world and productively guides future research, the greater confidence
scientists have in the validity of those hypotheses. Unifying scientific theories are built up from many
component hypotheses that have withstood repeated tests against observations.
Isn't science really
about proven facts?
Science
is not the mastery of a body of unchanging scientific "facts", but a
way of inquiring about our physical environment. It provides a way of understanding, explaining, and
integrating our observations of the natural world. While observations form the foundation of scientific
description, serious theoretical inquiry is the essence of science. Nothing could be more deadly to science
than to divorce it from the unifying theories which give observations
meaning. Theories provide the
predictions which suggest new observations and drive new discovery.
The
history of our changing scientific understanding of the universe, with new
theories replacing old, and previously accepted "facts" being
overturned by new discoveries, can be puzzling to someone who has learned
science as a body of facts. Furthermore,
uncertainty or sharp disagreement within the scientific community are often
seen as failures of science rather than expressions of its very strength.
Aren't theories about
the past untestable?
Frequent
claims are made that the historical sciences (cosmology, astronomy, geology,
evolutionary biology, anthropology, archaeology) deal with unrepeatable events
and are therefore not experimental.
Furthermore, because past events and processes are not directly
observable, theories of origins are deemed inferior or less certain than
studies of present processes. This
view commonly finds expression in statements like: "No one was there so we
can never know what really happened." This view is false. The historical sciences are no less
scientific, or testable, than the "hard sciences." Predictions made by hypotheses in these
fields are continually being tested by new observations. Predictions are tested against each new
observation or analysis. Obtaining
data from a newly analyzed sample or newly described locality is no different
methodologically than obtaining data from a new experimental trial. In both cases, the new observations can
be tested against expectations based on previous experience and theoretical
predictions. If the predictions deduced from a hypothesis are not supported by
new observations then that hypothesis is modified or rejected. Scientific research proceeds by an
almost continual process of hypothesis creation and testing. Many past theories in the historical
sciences have been discarded with the accumulation of new observations and the
development of new theories of greater explanatory power.
Like
all scientific disciplines, geology and paleontology proceed by testing the
predictions of existing models and theories. Predictions are tested against each new observation or
analysis. Obtaining data from a
newly analyzed sample or newly described locality is no different
methodologically than obtaining data from a new experimental trial. In both cases, the new observations can
be tested against expectations based on previous experience and theoretical
predictions. In stratigraphy or
sedimentology, for example, the measurement and description of each new rock
outcrop or subsurface core is a test of working hypotheses based on present understanding. For example, if a specific rock unit is
interpreted to be part of a meandering river system, then specific predictions
can be made concerning the geometry of this rock body and the characteristics
and distribution of associated sedimentary rocks. In modern meandering river systems a whole complex of
sedimentary environments are present: channel and point bar deposits, levees,
crevasse splays, overbank flood deposits, abandoned channels, freshwater lakes,
etc. Each of these environments
has its characteristic spatial relationships, sediment types, depositional
features, and associated biota. If
the original hypothesis of a meandering river system was correct, then further
exploration and sampling of the area should reveal the predicted geologic
features and their predicted spatial and temporal relationships. If the new observations are contrary to
these predictions, then the hypothesis must be modified, or if necessary,
abandoned.
Isn't one theory as
good as another?
Many theories may be proposed
to explain the same set of observations. However, not all theories are given
equal weight by the scientific community.
Some are rejected by the preponderance of practicing scientists, and
others remain at the fringes provoking critical examination. How do we distinguish a good theory from
a bad one? How do we establish
relative confidence in theories?
Criteria for a good scientific theory include:
1)
explanatory power;
2)
predictive power (testable expectations);
3) fruitfulness (ability to generate new questions
and new directions of research);
and
4)
aesthetics (eg. beauty, simplicity, symmetry).
Biological
evolution (descent with modification from a common ancestor), plate tectonics
(the mobility and recycling of the Earth's crust) , and the Big Bang theory are
examples of extremely well-substantiated theories that provide an
interpretative framework for a vast amount of observational evidence. These
powerful unifying theories continue to generate fruitful and testable
hypotheses that drive new discovery.
Isn't science based on
an atheistic philosophy?
The
answer is an emphatic NO! Science
is a methodology, a limited way of knowing about the natural world. Scientific research proceeds by the
search for chains of cause-and-effect, and confines itself to the investigation
of "natural" entities and forces. This self limitation is sometimes referred to as
"methodological naturalism."
Science does not affirm or deny the existence of a creator -- it is simply silent on the existence or action of God. The confirmation or denial of ultimate
causes is beyond its capacity to investigate. Methodological naturalism describes what empirical inquiry
is, it certainly is not a
statement of the nature of all reality.
Science pursues truth within very narrow limits. Our most profound questions about the
nature of reality (questions of meaning and purpose and morality) , while they
may arise from within science, are theological or philosophical in nature and
their answers lie beyond the reach of science.