CHAPTER VI
GOLDEN AGE OF GREEK SCIENCES
Science had made a great advance as a result of the researches and theories of the atomists. A consistent mechanical theory of matter and the universe had been set forth. Science and philosophy were stripped of many of the old superstitions that had clung to them. The leading theories invented were based on logical principles. While these changes were being worked out, numerous inventions of scientific instruments and apparatus were made and systematic methods of studying science were organized. These furnished the means for still greater progress.
The apparent completeness of the mechanical theory of the universe satisfied the inquiring intellect. The excitement caused by the scientific discussions and discoveries from the time of Heraclitus subsided. But after a short intervening period, when public attention had been largely centered on practical affairs, there was a reaction against science. When scientific principles were quoted a tendency was shown to question their validity and usefulness. This resulted in inquiries into the sources of knowledge and conduct and ushered in a new intellectual era that is now known as the Humanistic period which, beginning about 450 B. C., extended to 400 B. C.
The Sophists, who were teachers of rhetoric and were accustomed to studying the phrasing of verbal statements, became active in searching for the foundations of thought.
The Protagorean theory of knowledge was based on Empedocles's doctrine that the inner atoms advance to meet the outer ones. Perception is the resultant product of these atoms when they collide. They believed that this perception is something else than the perceiving subject and is also something different from the object giving birth to the perception. It is conditioned by both, but has a distinct existence. The doctrine of the subjectivity of sense perception was developed in explanation of this psychological problem. From this it followed that knowledge must be strictly personal and could be true only under conditions existing at the instant of perception. These limitations caused Protagoras to advance his theory of relativity, which teaches that man is the measure of all things. Facts are what appear to each individual to be statements of truth. Isocrates, Plato, Aristotle, and Socrates were the leaders of this intellectual movement.
Socrates developed the Pythagorean theory of intelligible forms. The specific qualities of the senses belong to the realm of perception. When these are withdrawn from an object of thought there remains only the form or idea. Therefore it is evident that pure, intelligible forms constitute the essences of things. The early scientists, such as Democritus, thought, perhaps, in terms of atom forms. Socrates, Plato, and later teachers looked upon forms as conceptions of similar logical elements. Knowledge, in the view of Democritus, was essentially rationalistic. Plato considered knowledge as having ethical and æsthetic purposes within itself.
Each of these types of rationalism stimulated Greek thought and resulted in a strong impulse to philosophical and scientific investigation. They prepared the outlook for Aristotle.
Science had been hampered by the confusion raised by the discussions relating to forms. Aristotle realized that proper progress in logic, physics, and ethics, the leading sciences of his time, could not be made unless the essential nature of science were kept in view. He saw that knowledge of the forms of correct thinking can be understood only by keeping in view the object of thought and this requires definite ideas of the general relations of knowledge and its objects. The study of general relationships led to the study of particular or special relations. The connection of general with particular ideas was unfolded, and Aristotle saw that conceiving, understanding, and proving result from the deduction of particular from universal, or general, ideas. Therefore science consists in deriving or deducing facts acquired through perception from their general grounds or phenomena. The logical form of the syllogism naturally suggested itself to Aristotle when engaged with these thoughts and the invention of the syllogism was one of the most brilliant contributions to knowledge made by the Greeks.
The logical results of the invention of syllogistic forms suggested a solution of the problem of true reality which Aristotle showed was the essence that unfolds in phenomena themselves. This led to fruitful scientific results. Plato and his contemporaries unified mathematics, formulated the definitions logically, and demonstrated correct methods of criticism and proof. A point was shown to be the boundary of a line; while a line is the boundary of a surface, and a surface the boundary of a solid. This concrete definition of scientific elements progressed through the use of analytic methods, by proceeding from the known to the unknown, and led to the discovery of tests for scientific assumptions and of synthetic proof. None of the earlier philosophers possessed anything like the progressive tools Aristotle placed in the hands of scientists. Their use quickly led to a general review of knowledge and a great increase in the number of sciences.