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Aristotle, Galileo, and Pasteur can be said to have contributed
significantly, each in his own way, to the development of “The Scientific
Method.” Discuss. What is the scientific method? In general, this method has
three parts, which we might call (1) gathering evidence, (2) making a
hypothesis, and (3) testing the hypothesis. As scientific methodology is
practiced, all three parts are used together at all stages, and therefore no
theory, however rigorously tested, is ever final, but remains at all times
tentative, subject to new observation and continued testing by such observation.
Hellenic science was built upon the foundations laid by Thales and Pythagoras.
It reached its zenith in the works of Aristotle and Archimedes.
Aristotle
(384-322 B.C.) represents the first tradition, that of qualitative forms and
teleology. He was, himself, a biologist whose observations of marine organisms
were unsurpassed until the 19th century. Biology is essentially
teleological--the parts of a living organism are understood in terms of what
they do in and for the organism--and Aristotle's biological works provided the
framework for the science until the time of Charles Darwin. Aristotle was able
to make a great deal of sense of observed nature by asking of any object or
process: what is the material involved, what is its form and how did it get that
form, and, most important of all, what is its purpose? What should be noted is
that, for Aristotle, all activity that occurred spontaneously was natural.
Hence, the proper means of investigation was observation. Experiment, that is,
altering natural conditions in order to throw light on the hidden properties and
activities of objects, was unnatural and could not, therefore, be expected to
reveal the essence of things. However, the establishment of the importance of
classifying knowledge and of observation as well as the introduction of the
deductive method of reasoning can be taken as Aristotle’s most significant
contributions to the scientific method. Even after the intellectual revolutions
of centuries to follow, Aristotelian concepts and ideas remained embedded in
Western thinking. The critical tradition of science began with Copernicus in the
sixteenth century. It eventually led to the work of Galileo (1564-1642), which criticised the very roots of the Aristotelian world system. With the invention
of the telescope Galileo, in quick succession, announced that there were
mountains on the Moon, satellites circling Jupiter, and spots upon the Sun.
Moreover, the Milky Way was composed of countless stars whose existence no one
had suspected until Galileo saw them. Galileo attacked the problems of the
Earth's rotation and its revolution by logical analysis.
Bodies do not fly off
the Earth because they are not really revolving rapidly, even though their speed
is high. In revolutions per minute, any body on the Earth is going very slowly
and, therefore, has little tendency to fly off. Bodies fall to the base of
towers from which they are dropped because they share with the tower the
rotation of the Earth. Hence, bodies already in motion preserve that motion when
another motion is added. So, Galileo deduced, a ball dropped from the top of a
mast of a moving ship would fall at the base of the mast. If the ball were
allowed to move on a frictionless horizontal plane, it would continue to move
forever. Hence, Galileo concluded, the planets, once set in circular motion,
continue to move in circles forever. Therefore, Copernican orbits exist. Galileo
never acknowledged Kepler's ellipses; to do so would have meant abandoning his
solution to the Copernican problem. Galileo's originality as a scientist lay in
his method of inquiry. First he reduced problems to a simple set of terms on the
basis of everyday experience and common-sense logic.
Then he analyzed and
resolved them according to simple mathematical descriptions. The success with
which he applied this technique to the analysis of motion opened the way for
modern mathematical and experimental physics. Louis Pasteur (1822-1895) was a
French chemist and microbiologist. His discovery that most infectious diseases
are caused by germs, known as the germ theory of disease, is one of the most
important in medical history. Pasteur's phenomenal contributions to microbiology
and medicine can be summarized as follows. First, he championed changes in
hospital practices to minimize the spread of disease by microbes. Second, he
discovered that weakened forms of a microbe could be used as an immunization
against more virulent forms of the microbe.
Third, Pasteur found that rabies was
transmitted by agents so small they could not be seen under a microscope, thus
revealing the world of viruses. As a result he developed techniques to vaccinate
dogs against rabies, and to treat humans bitten by rabid dogs. And fourth,
Pasteur developed pasteurization, a process by which harmful microbes in
perishable food products are destroyed using heat, without destroying the food.
Pasteur's work is not simply the sum of his discoveries. It also represents the
revolution of scientific methodology. Pasteur superimposed two indisputable
rules of modern research: the freedom of creative imagination necessarily
subjected to rigorous experimentation. His work became the foundation for the
science of microbiology, and a cornerstone of modern medicine.
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