User:SteveMcCluskey/backup

From Wikipedia, the free encyclopedia

Tracing the history of atomism is hazardous, for we all know now that the world is made up of atoms and are tempted to project our ideas onto the past. It is all too easy to look at past concepts and consider that when Democritus, or Dharmakirti, or Hobbes discussed how matter is made up of small particles, their idea was the same as a similar modern one. Even worse, there is a temptation to "award points" to historical figures for having ideas that came close to modern ones, without considering the adequacy of the contemporary evidence they had to support those ideas. We must always remind ourselves that an answer that comes close is not necessarily the right answer, and that it's possible to have the right answer for the wrong reasons and good reasons for the wrong answer.

In natural philosophy, atomism is the theory that all the objects in the universe are composed of very small, indestructible elements - atoms. Or, stated in other words, all of reality is made of indivisible basic building blocks. The word atomism derives from the ancient Greek word atomos which means "that which cannot be cut into smaller pieces".

Contents

[edit] Traditional atomism in philosophy

The word "atom" is used in two distinct divisions: the atoms of physical science, and that of philosophy. Atomism is traditionally associated with the latter, where philosophers have argued that the basic building blocks of reality, and which make up absolutely anything that exists, are incredibly tiny objects that do not have physical parts, cannot be split, divided or cut, and which are either point-sized (sizeless) or they have a tiny size. Those that have a tiny size are called Democritean atoms. This was the case for the Greek theories of atomism. Indian Buddhists, such as Dharmakirti and others, also contributed to well-developed theories of atomism, and which involve momentary (instantaneous) atoms, that flash in and out of existence. The tradition of atomism leads to the position that only atoms exist, and there are no composite objects (objects with parts), which would mean that human bodies, clouds, planets, and whatnot all do not exist. This consequence of atomism was openly discussed by atomists such as Democritus, Hobbes, and perhaps even Kant (there is a debate over whether or not Kant was an atomist) among others, and it is also called mereological nihilism or metaphysical nihilism. In contemporary philosophy, atomism is not as popular as it has been in past times, because many contemporary philosophers are not willing to argue that only atoms exist, wherein there are not any things like trees, etc.

[edit] Other issues to do with philosophy and atomism

If atomism is the idea that anything might ultimately consist of an aggregation of small units that cannot be sub-divided further, then "atomism" might be applied to even the aggregations of society or logic.

Accordingly, the term social atomism is used to denote the point-of-view that individuals rather than social institutions and values are the proper subject of analysis since all properties of institutions and values merely accumulate from the striving of the individual. [1]

Similarly, Bertrand Russell developed logical atomism in an attempt to identify the atoms of thought, the pieces of thought that cannot be divided into smaller pieces of thought.

The atoms that chemists and physicists of the early 1800s thought were indivisible turned out to be composed of even smaller entities: electrons, neutrons, and protons. Similarly, experiments showed that protons and neutrons are made of even smaller quarks. So, the trend of empirical evidence for ever-smaller particles inside "atoms" suggests the question: "Is matter infinitely divisible?" Experiment likely can never answer that question; who can say that the experimentalists and the theorists will not contrive some even more powerful means to smash what some previously had thought to be "indivisible" to find that it is composed of even smaller pieces of matter and energy?

How about space and time? In many mathematical descriptions, space and time are infinitely divisible. That is, for example, many classical descriptions of space assume that between any two points of space, there will be another point of space. But some current theorists suggest that even space and time are composed of measurable quanta that "cannot be cut into smaller pieces" to observe.

[edit] Indian atomism

 This section does not cite any references or sources. (May 2008)
Please help improve this section by adding citations to reliable sources. Unverifiable material may be challenged and removed.

As Hindu and Buddhist theology began to mature, a number of distinct schools of philosophy emerged in India. The origins of Indian atomism remain unclear; the pre-Greek materialist philosopher Uddalaka seems to have laid some of the groundwork for atomism, and the ancient “Sassata-Vada” doctrine of eternalism, which held that elements are eternal, is also suggestive of a possible starting point for atomism (Gangopadhyaya 1981). While there is some disagreement among scholars as to the origin of Indian atomism, the general consensus is that the Indian and Greek versions of atomism developed independently. Some scholars doubt this, given the similarities between Indian atomism and Greek atomism and the proximity of India to scholastic Europe, as well as there being some evidence suggesting the possibility of Pythagoras visiting India. The earliest schools of Indian atomism however, began to develop before Greek atomism and before the time of Leucippus.

A number of important branches of Indian philosophy became involved with atomism to varying extents, particularly the Nyaya-Vaisesika, Jaina and Buddhist schools.

Indian atomism in the Middle Ages was still mostly philosophical and/or religious in intent, though it was also scientific. Because the “infallible Vedas”, the oldest Hindu texts, do not mention atoms (though they do mention elements), atomism was not orthodox in many schools of Hindu philosophy, although accommodationist interpretations or assumptions of lost text justified the use of atomism for non-orthodox schools of Hindu thought. The Buddhist and Jaina schools of atomism however, were more willing to accept the ideas of atomism. Still, Indian theories of atomism were at least on par in terms of complexity and explanatory power with those of the Greek atomists.

[edit] Nyaya-Vaisesika school

The Nyaya-Vaisesika school had one of the earliest forms of atomism; scholars date the Nyaya and Vaisesika texts from the 6th century BC to the 1st century BC. Like the Buddhist atomists, the Vaisesika had a pseudo-Aristotelian theory of atomism. They posited the four elemental atom types, but in Vaisesika physics atoms had 24 different possible qualities, divided between general (what we would call extensive) properties and specific (intensive) properties. Like the Jaina school, the Nyaya-Vaisesika atomists had elaborate theories of how atoms combine. In both Jaina and Vaisesika atomism, atoms first combine in pairs (dyads), and then group into trios of pairs (triads), which are the smallest visible units of matter. This parallels with the structure of modern atomic theory, in which pairs or triplets of supposedly fundamental quarks combine to create most typical forms of matter.

[edit] Buddhist school

The Buddhist atomists had very qualitative, Aristotelian-style atomic theory. According to ancient Buddhist atomism, which probably began developing before the 4th century BC, there are four kinds of atoms, corresponding to the standard elements. Each of these elements has a specific property, such as solidity or motion, and performs a specific function in mixtures, such as providing support or causing growth. Like the Hindu Jains, the Buddhists were able to integrate a theory of atomism with their theological presuppositions. Later Indian Buddhist philosophers, such as Dharmakirti and Dignāga, considered atoms to be point-sized, durationless, and made of energy.

[edit] Jaina school

The most elaborate and well-preserved Indian theory of atomism comes from the philosophy of the Jaina school, dating back to at least the first century BC. The Jains envisioned the world as consisting wholly of atoms, except for souls. Their concept of atoms was very similar to classical atomism, differing primarily in the specific properties of atoms. Each atom, according to Jaina philosophy, has one kind of taste, one smell, one color, and two kinds of touch, though it is unclear what was meant by “kind of touch”. Atoms can exist in one of two states: subtle, in which case they can fit in infinitesimally small spaces, and gross, in which case they have extension and occupy a finite space. Although atoms are made of the same basic substance, they can combine based on their eternal properties to produce any of six “aggregates,” which seem to correspond with the Greek concept of “elements”: earth, water, shadow, sense objects, karmic matter, and unfit matter. To the Jains, karma was real, but was a naturalistic, mechanistic phenomenon caused by buildups of subtle karmic matter within the soul. They also had detailed theories of how atoms could combine, react, vibrate, move, and perform other actions, all of which were thoroughly deterministic.

[edit] Greek atomism

[edit] The puzzle of similarities and differences

The various arguments of atomism trace the various attempts to understand sufficiently why some things of the world, such as different fires, are so similar in appearance and yet other things, such as dark nights, are so different from their opposites, as fires compared to dark nights.

Around 475 BC, Parmenides in his philosophical poem On Nature posed the puzzle this way.

Consider how very much one fire is like another fire.
But notice how opposite in nature all the dark nights are to fire. [2]

As the solution for that puzzle, Parmenides stated that, despite the appearances of differences, all things are composed of the same solitary, never-created, never-ending, eternal Being—the One—the "it" that is "without beginning and without end." [3] While insisting on this uncreated being, Parmenides insisted that what is not, is not; this means that there is no empty space or void. Thus his theory was not atomistic, for Parmenides did not consider the eternal being to be composed of distinct units. Parmenides theory did provide two important features that atomistic theories later would employ: 1) asserting that all objects of the physical world consisted of some never-created and never-ending hidden substance and 2) explaining the differences among objects to be the result of different configurations of the never-ending substance hidden inside them.

[edit] Are there different elements?

Empedocles about 450 BC looked at the puzzle of similarities and differences and conjectured in a poem also titled "On Nature" that things of similarity, like fires, are composed of the same proportions of the elements fire, air, earth, and water. On the other hand, opposite substances, like fire and dark night, have inverse or otherwise contrasting proportions of the four elements.

And the elemental substances of fire, air, earth, and water are never-created and never-ending. Accordingly, changes in the physical world, such as growth and decay, consist merely of shifts in the combinations of the elements fire, air, earth, and water. [4]

But Empedocles was not proposing atomism. For even though Empedocles postulated that there were the four different elements composing the hidden substance of physical objects, he did not discuss the internal structure of these different elements. The four elements fire, air, earth, and water were continuous, not discrete particles.

[edit] Is there an ultimate, indivisible unit of matter?

Greek stamp honoring Democritus and his modern significance
Greek stamp honoring Democritus and his modern significance

In the late fifth century BC, Democritus and Leucippus taught that the hidden substance in all physical objects consists of different arrangements of 1) atoms and 2) void. Both atoms and the void were never created, and they will be never ending. Democritus became famous for this idea, but he followed closely what his teacher Leucippus taught (Lloyd 1970, 45-48).

The void is infinite and provides the space in which the atoms can pack or scatter differently. The different possible packings and scatterings within the void make up the shifting outlines and bulk of the objects that we feel, see, eat, hear, smell, and taste. We sense hot and cold, but hot and cold have not real existence. For hot and cold are simply sensations produced in us by the different packings and scatterings of the atoms in the void that compose the object that we sense as being "hot" or "cold."

Very few fragments of Democritus's writings have survived, nevertheless, his ideas are represented in Aristotle's criticisms of atomism and in the derivative works of Democritus's followers, such as Lucretius's On the Nature of Things. These derivative works by Democritus's allow us to work out several segments of his theory on how the universe began its current stage. The atoms and the void are eternal. And after collisions that shatter large objects into smaller objects, the resulting dust, still composed of the same eternal atoms as the prior configurations of the universe, falls into a whirling motion that draws the dust into larger objects again to begin another cycle.

Democritus found fault with the philosophers around him who pandered to the unwitting hungers and passions of people that cause them to yearn for an "intelligent designer". The workings of the universe are entirely mechanical, driven by what he called the "vibrations," the velocities and impacts of the constituent atoms. He explained that things happen because of what he called "necessity," the mechanistic collisions and aggregations of the atoms according to their own "nature." He explained the common person's belief in gods to be the result of animal passions, faulty understanding, and ignorance of how the correlated motions of the atoms caused powerful displays of nature such as thunder, lightning, and earthquakes.

[edit] Geometry and atoms

Atom Polyhedron Number of Faces Number of Triangles
Fire Tetrahedron Tetrahedron 4 24
Air Octahedron Octahedron 8 48
Water Icosahedron Icosahedron 20 120
Earth Cube Hexahedron (cube) 6 24
Geometrical basis of atoms according to Plato

Plato (c. 427—c. 347 BC) objected to the mechanistic purposelessness of the atomism of Democritus. He argued that atoms just crashing into other atoms could never produce the beauty and form of the world. In the Timaeus, (28B - 29A) Plato insisted that the cosmos was not eternal but was created, although its creator framed it after an eternal, unchanging model.

One part of that creation were the atoms of fire, air, water, and earth. But Plato did not consider the atoms to be the most basic level of reality, for in his view they were made up of an unchanging level of reality, which was mathematical. The atoms were geometric solids, the faces of which were, in turn, made up of triangles. The square faces of the cube were each made up of four isosceles right-angled triangles and the triangular faces of the tetrahedron, octahedron, and icosahedron were each made up of six right-angled triangles.

He postulated the geometric structure of the atoms of the four elements as summarized in the table to the right. The cube, with its flat base and stability, was assigned to earth; the tetrahedron was assigned to fire because its penetrating points and sharp edges made it mobile. The points and edges of the octahedron and icosahedron were blunter and so these less mobile bodies were assigned to air and water. Since atoms could be decomposed into triangles, and the triangles reassembled into atoms of different elements, Plato's model offered a plausible account of changes among the primary substances (Cornford 1957, 210-239; Lloyd 1970, 74-7).

[edit] The Rejection of atoms

Sometime before 330 BC Aristotle asserted that the elements of fire, air, earth, and water were not made of atoms, but were continuous. Aristotle considered the existence of a void, which was required by atomic theories, to violate physical principles. Change took place not by the rearrangement of atoms to make new structures, but by transformation of matter from what it was in potential to a new actuality. A piece of wet clay, when acted upon by a potter, takes on its potential to be an actual drinking mug. Aristotle has often been criticized for rejecting atomism, but a study of his life and thought by a leading historian of Greek science noted "The atomic theories of Democritus and Plato were undoubtedly most ingenious, but they too were, of course, pure speculations, incapable of being put to any experimental test." (Lloyd 1968, 165; see also Lloyd 1970, 108-9)

[edit] Atoms and ethics

Epicurus (341-270) studied atomism with Nausiphanes who had been a student of Democritus. Although Epicurus was certain of the existence of atoms and the void, he was less sure we could adequately explain specific natural phenomena such as earthquakes, lightning, comets, or the phases of the Moon (Lloyd 1973, 25-6). Few of Epicurus's writings survive and those that do reflect his interest in applying Democritus's theories to assist people in taking responsibility for themselves and for their own happiness—since he held there are no gods around that can help them.

Three hundred years later, Lucretius in his epic poem On the Nature of Things would depict Epicurus as the hero who crushed the monster Religion through educating the people in what was possible in the atoms and what was not possible in the atoms. However, Epicurus expressed non-aggression to Religion or any other face of violence in the following statement. "The man who best knows how to meet external threats makes into one family all the creatures he can; and those he can not, he at any rate does not treat as aliens; and where he finds even this impossible, he avoids all dealings, and, so far as is advantageous, excludes them from his life." [5]

[edit] The exile of atomism

While Aristotelian philosophy eclipsed the importance of the atomists, their work was still preserved and exposited through commentaries on the works of Aristotle. In the 1st century, Galen (129-216 AD) presented extensive discussions of the Greek atomists, especially Epicurus, in his Aristotle commentaries. In the West, atomism was largely an ignored footnote of philosophy, as it was incompatible with Aristotelianism. According to historian of atomism Joshua Gregory, there was no serious work done with atomism from the time of Galen until Gassendi and Descartes resurrected it in the 16th century; “the gap between these two ‘modern naturalists’ and the ancient Atomists marked the exile of the atom” and “it is universally admitted that the Middle Ages had abandoned Atomism, and virtually lost it.” However, scholars still had Aristotle’s texts on atomism, and it seems unlikely the ideas of atomism could have been lost in the West. Rather, it was studied in the universities as an incorrect, pre-Aristotelian system of physics. Still, “the exile of the atom” is an appropriate description of the interim between the ancient Greeks and the revival of Western atomism in the 16th century, in view of atomism’s success elsewhere during that time. If the atom was in exile from the west, it was exiled to India and to Islam where atomistic traditions continued.

[edit] Islamic atomism

Atomistic philosophies are found very early in Islam, and represent a synthesis of the Greek and Indian ideas. Like both the Greek and Indian versions, Islamic atomism was a charged topic that had the potential for conflict with the prevalent religious orthodoxy. Yet it was such a fertile and flexible idea that, as in Greece and India, it flourished in some schools of Islamic thought.

The most successful form of Islamic atomism was in the Asharite school of philosophy, most notably in the work of the philosopher al-Ghazali (1058-1111). In Asharite atomism, atoms are the only perpetual, material things in existence, and all else in the world is “accidental” meaning something that lasts for only an instant. Nothing accidental can be the cause of anything else, except perception, as it exists for a moment. Contingent events are not subject to natural physical causes, but are the direct result of God’s constant intervention, without which nothing could happen. Thus nature is completely dependent on God, which meshes with other Asharite Islamic ideas on causation, or the lack thereof (Gardet 2001).

Other traditions in Islam rejected the atomism of the Asharites and expounded on many Greek texts, especially those of Aristotle. An active school of philosophers in Spain, including the noted commentator Averroes (1126-1198 AD) explicitly rejected the thought of al-Ghazali and turned to an extensive evaluation of the thought of Aristotle. Averroes commented in detail on most of the works of Aristotle and his commentaries did much to guide the interpetation of Aristotle in Jewish and Christian scholastic thought. His works were neglected in the Islamic world, however.

[edit] Atomic Renaissance

Aristotle held sway in the universities of Europe for most of the Middle Ages, and even through the time of Newton Aristotelian physics was the standard, although other theories were beginning to be introduced to university curriculum by then (Kargon 1966). But by the late 16th century, criticism of Aristotle was mounting. The experimental philosophy was gaining ground, and with the evidence weighing in against the old physics, atomism soon reappeared in new forms. The main figures in the rebirth of atomism were Rene Descartes, Pierre Gassendi, and Robert Boyle, but there were many important ancillary figures as well.

One of the first groups of atomists in England was a cadre of amateur scientists known as the Northumberland circle, led by Henry Percy (1585-1632 AD), the 9th Earl of Northumberland. Although they published little of account, they helped to disseminate atomistic ideas among the burgeoning scientific culture of England, and may have been particularly influential to Francis Bacon, who became an atomist around 1605, though he later rejected some of the claims of atomism. Though they revived the classical form of atomism, this group as among the scientific avant-garde: the Northumberland circle contained nearly half of the confirmed Copernicans prior to 1610 (the year of Galileo’s The Starry Messenger). Other influential atomists of late 16th and early 17th centuries include Giordano Bruno, Thomas Hobbes (who also changed his stance on atomism late in his career), and Thomas Hariot. A number of different atomistic theories were blossoming in France at this time, as well (Clericuzio 2000).

A more well-known advocate of atomism in the early 16th century was Galileo Galilei (1564-1642 AD). He first published a work based on atomism in 1612, Discourse on Floating Bodies (Redondi 1969). In The Assayer, Galileo offered a more complete physical system based on a corpuscular theory of matter, in which all phenomena—with the exception of sound—are produced by “matter in motion”. Galileo found some of the basic problems with Aristotelian physics through his experiments, and he utilized a theory of atomism as a partial replacement, but he was never unequivocally committed to it. For example, his experiments with falling bodies and inclined planes led him to the concepts of circular inertial motion and accelerating free-fall. These notions contradicted the Aristotelian theories of impulse and natural place, which dictated that bodies fall equal distances in equal times and all motion (except that of the heavens) is finite. Atomism could not explain the law of fall, but was consistent with his concept of inertia, since motion was conserved in ancient atomism (but not in Aristotelian physics). Galileo scholar Pietro Redondi has even suggested that the root of the church’s persecution of Galileo was his rejection of Aristotelian philosophy and championing of atomism (Redondi 1969). Although that was certainly not the whole story behind the so-called Galileo Affair, it is another intriguing element and may have a germ of truth.

Despite the success (and controversy) generated by 16th and 17th century atomists, atomism was not fully revived until Descartes and Gassendi published their new physics systems based on corpuscular (in the case of Descartes) and atomistic (in the case of Gassendi) theories. Descartes’ mechanical philosophy of corpuscularism had much in common with atomism, and may be considered in some sense another version of it. Descartes (1596-1650 AD) thought everything physical in the universe to be made of tiny “corpuscles” of matter. Like the ancient atomists, Descartes claimed that sensations, such as taste or temperature, are caused by the shape and size of tiny pieces of matter. The main difference between atomism and corpuscularism was the existence of the void. For Descartes, there could be no vacuum, and all matter was constantly swirling to prevent a void as corpuscles moved through other matter. Another key distinction between Descartes’ corpuscularism and classical atomism is Descartes’ concept of mind/body duality, which allowed for an independent realm of existence for thought, soul, and most importantly, God. Gassendi’s system was much closer to classical atomism, but without the atheistic undertones.

Pierre Gassendi (1592-1655 AD) was a Catholic priest from France who was also an avid natural philosopher. He was particularly intrigued by the Greek atomists, so he set out to “purify” atomism from its heretical and atheistic philosophical conclusions (Dijksterhius 1969). Gassendi formulated his atomistic conception of mechanical philosophy partly in response to Descartes; he particularly opposed Descartes’ reductionist view that only purely mechanical explanations of physics are valid, as well as the application of geometry to the whole of physics (Clericuzio 2000).

The final form of atomism that came to be accepted by most English scientists after Robert Boyle (1627-1692 AD) was an amalgam of the two French systems. In The Sceptical Chymist (1661), Boyle shows some of the problems with Aristotelian physics that arise from chemistry experimentation, and offers up atomism as a possible explanation. The unifying principle that led to the acceptance of this hybrid atomism was the mechanical philosophy, which was becoming widely accepted by Western scientists. Despite the problems with atomism, it was clear by the end of the 17th century that it was a better alternative than Aristotelian physics, especially since it was compatible with the mechanical philosophy.

[edit] A different atom for each element

By the late 1700s, the useful practices of engineering and technology began to influence philosophical explanations for the composition of matter. Those who speculated on the ultimate nature of matter began to verify their "thought experiments" with some repeatable demonstrations, when they could.

In 1808, John Dalton assimilated the known experimental work of many people to summarize the empirical evidence on the composition of matter. He noticed that distilled water everywhere analyzed to the same elements, hydrogen and oxygen. Similarly, other purified substances decomposed to the same elements in the same proportions by weight.

Therefore we may conclude that the ultimate particles of all homogeneous bodies are perfectly alike in weight, figure, etc. In other words, every particle of water is like every other particle of water; every particle of hydrogen is like every other particle of hydrogen, etc.

Furthermore, he concluded that there was a unique atom for each element, using Lavoisier's definition of an element as a substance that could not be analyzed into something simpler. Thus, Dalton concluded the following.

Chemical analysis and synthesis go no farther than to the separation of particles one from another, and to their reunion. No new creation or destruction of matter is within the reach of chemical agency. We might as well attempt to introduce a new planet into the solar system, or to annihilate one already in existence, as to create or destroy a particle of hydrogen. All the changes we can produce, consist in separating particles that are in a state of cohesion or combination, and joining those that were previously at a distance.

And then he proceeded to give a list of relative weights in the compositions of several common compounds, summarizing: [6]

1st. That water is a binary compound of hydrogen and oxygen, and the relative weights of the two elementary atoms are as 1:7, nearly;
2nd. That ammonia is a binary compound of hydrogen and azote nitrogen, and the relative weights of the two atoms are as 1:5, nearly...

Dalton concluded that the fixed proportions of elements by weight suggested that the atoms of one element combined with only a limited number of atoms of the other elements to form the substances that he listed.

[edit] See also

[edit] External links

[edit] References

  • Clericuzio, Antonio. Elements, Principles, and Corpuscles; a study of atomism and chemistry in the seventeenth century. Dordrecht; Boston: Kluwer Academic Publishers, 2000.
  • Cornford, Francis MacDonald. Plato's Cosmology: The Timaeus of Plato. New York: Liberal Arts Press, 1957.
  • Dijksterhuis, E. The Mechanization of the World Picture. Trans. by C. Dikshoorn. New York: Oxford University Press, 1969. ISBN 0691023964
  • Firth, Raymond. Religion: A Humanist Interpretation. Routledge, 1996. ISBN 0415128978.
  • Gangopadhyaya, Mrinalkanti. Indian Atomism: history and sources. Atlantic Highlands, New Jersey: Humanities Press, 1981. ISBN 039102177X
  • Gardet, L. “djuz’” in Encyclopaedia of Islam CD-ROM Edition, v. 1.1. Leiden: Brill, 2001.
  • Gregory, Joshua C. A Short History of Atomism. London: A. and C. Black, Ltd, 1981.
  • Kargon, Robert Hugh. Atomism in England from Hariot to Newton. Oxford: Clarendon Press, 1966.
  • Lloyd, G. E. R. Aristotle: The Growth and Structure of his Thought. Cambridge: Cambridge University Press, 1968. ISBN 0-521-09456-9
  • Lloyd, G. E. R. Early Greek Science: Thales to Aristotle. London: Chatto and Windus; New York: W. W. Norton, 1970. ISBN 0-393-00583-6
  • Lloyd, G. E. R. Greek Science After Aristotle. New York: W. W. Norton, 1973. ISBN 0-393-00780-4
  • Redondi, Pietro. Galileo Heretic. Translated by Raymond Rosenthal. Princeton, NJ: Princeton University Press, 1987. ISBN 069102426X
  • Taylor, C. C. W., translator, commentator. The Atomists, Leucippus and Democritus: a text and translation with commentary by C. C. W. Taylor. Toronto and Buffalo: University of Toronto Press, 1999. ISBN 0802043909

Category:History of chemistry Category:History of ideas Category:History of philosophy Category:History of physics Category:Philosophical terminology Category:Religious philosophy and doctrine