Democritus and Dalton's Theories
In 1803, John Dalton introduced his atomic idea to the world of chemistry. John Dalton is also called the Father of Modern Atomic Theory.
I. Atomism in Antiquity
Aristotle opposed the atomic ideas of Leucippus and Democritus a hundred or so years after they were originated. Those who thought called Aristotle their master opposed atoms, and since Epicurus was an atomist, he was opposed by the Stoics. Cicero, Seneca and Galen also opposed anything to do with atoms.
Hero of Alexandria made use of atoms to the process of something thinning out. He also denied the existence of an extended vacuum, but allowed the use of a vacuum between atoms.
Figures that were important within the church also spoke out against atoms. Dionysios, Lactantius and Augustine are also identified as being opposed to the idea of atoms.
II. Atomism in the Middle Ages
Many people used the word "atom" to refer the discontinuities. The most notable are Isidore, bishop of Seville, the Venerable Bede, and Hrabanus Maurus. Both William Conches and Vincent of Beauvais both showed knowledge of atomic thinking in their writings. Conches taught the ideas of Democritus. Vincent wrote an encyclopedia, but only shortly mentioned the idea of atoms.
De Rerum Natura was rediscovered in 1417. It was and still is the prime source for the ideas of Leucippus and Democritus.
III. Atomism in the Renaissance
Nicholas of Cusa once wrote "What dost thou understand by an atom?
Through discussion of the mechanism of infection, Girolamo Fracastoro supposed the existence of small, indivisible substances which convey the disease.
Peter Ramus broke with Aristotle early in his life. He presented a thesis that stated that "all that Aristotle has said is false." His opponents could not appeal to the authority of Aristotle to defend him, since doing so would be "begging the question." After one day of his ideas being attacked and defended, Ramus was awarded his degree with honors. Ramus was silenced by Pope, Francis I, in 1543, after publishing two "offensive" books that provoked violent reaction.
In 1588, Giordano Bruno wrote:
"The division of natural things has a limit; an indivisible something exists. The division of natural things attains the smallest and last parts which are not perceptible by the aid of human instruments."
Sebestian Basso wrote of particles of the first, second, and third, order of structures built up by bringing atoms together. J.C. Magnenus attempted to calculate the size of an atom.
Sennert told his students that there must be atoms of more than one type and that atoms joined together to form bodies. He used the fact that vapor from wine penetrated four layers of paper to show the minuteness of atoms. Another example that Sennert used was the fact that a large volume of vapor yielded a small drop of liquid. He also taught that atoms keep their essential form. For example, if pure gold and pure silver are completely mixed, the silver is dissolved and the gold remains, upon treatment of the mixture with nitric acid.
IV. Pierre Gassendi
Gassendi is considered to be the reviver of atomism, but atomism never really went away, it was just on the verge of dying out. Gassendi was successful in making atomism more widely known and acceptable, especially by separating a belief in atomism from the belief of atheism.
In 1649, Gassendi published his major work on which divided atomism into three sections: Logic, Physics, and Ethnics. This work was called Syntagma philosophiae Epicuri .
Pierre Gassendi describes the Greek position on atoms by saying that atoms can neither be created nor destroyed, are solid, have weight, and cannot be subdivided. Gassendi also taught that atoms are not just geometric points, but that although very small, atoms have a definite size.
Gassendi differs from the Greek ideas in that atoms have not been in existence forever, but were made by God. He believed that atoms move not of themselves, but as a gift from God. This idea freed atomism from atheism.
Gassendi also allows for the union of atoms to form groups, which he calls moleculae or corpuscula . These groups are held together by mechanical forces such as hook-eyes or antlers, instead of attractive forces.