References to the concept of atomism and its atoms appeared in both ancient Greek and ancient Indian philosophical traditions. The ancient Greek atomists theorized that nature consists of two fundamental principles: atom and void. Unlike their modern scientific namesake in atomic theory, philosophical atoms come in an infinite variety of shapes and sizes, each indestructible, immutable and surrounded by a void where they collide with the others or hook together forming a cluster. Clusters of different shapes, arrangements, and positions give rise to the various macroscopic substances in the world.
The particles of chemical matter for which chemists and other natural philosophers of the early 19th century found experimental evidence were thought to be indivisible, and therefore were given the name "atom", long used by the atomist philosophy. Although the connection to historical atomism is at best tenuous, elementary particles have become a modern analog of philosophical atoms.
Philosophical atomism is a reductive argument; not only that everything is composed of atoms and void, but that nothing they compose really exists: the only things that really exist are atoms ricocheting off each other mechanistically in an otherwise empty void. Atomism stands in contrast to a substance theory wherein a prime material continuum remains qualitatively invariant under division (for example, the ratio of the four classical elements would be the same in any portion of a homogeneous material).
In the 5th century BCE, Leucippus and his pupil Democritus proposed that all matter was composed of small indivisible particles called atoms. Nothing whatsoever is known about Leucippus except that he was the teacher of Democritus. Democritus, by contrast, was a prolific writer, who wrote over eighty known treatises, none of which have survived to the present day complete. However, a massive number of fragments and quotations of his writings have survived. These are the main source of information on his teachings about atoms. Democritus's argument for the existence of atoms hinged on the idea that it is impossible to keep dividing matter for infinity and that matter must therefore be made up of extremely tiny particles.
Democritus believed that atoms are too small for human senses to detect, they are infinitely many, they come in infinitely many varieties, and that they have always existed. They float in a vacuum, which Democritus called the "void", and they vary in form, order, and posture. Some atoms, he maintained, are convex, others concave, some shaped like hooks, and others like eyes. They are constantly moving and colliding into each other. Democritus wrote that atoms and void are the only things that exist and that all other things are merely said to exist by social convention. The objects humans see in everyday life are composed of many atoms united by random collisions and their forms and materials are determined by what kinds of atom make them up. Likewise, human perceptions are caused by atoms as well. Bitterness is caused by small, angular, jagged atoms passing across the tongue; whereas sweetness is caused by larger, smoother, more rounded atoms passing across the tongue.
Parmenides denied the existence of motion, change and void. He believed all existence to be a single, all-encompassing and unchanging mass (a concept known as monism), and that change and motion were mere illusions. This conclusion, as well as the reasoning that led to it, may indeed seem baffling to the modern empirical mind, but Parmenides explicitly rejected sensory experience as the path to an understanding of the universe, and instead used purely abstract reasoning. Firstly, he believed there is no such thing as void, equating it with non-being (i.e. "if the void is, then it is not nothing; therefore it is not the void"). This in turn meant that motion is impossible, because there is no void to move into.  He also wrote all that is must be an indivisible unity, for if it were manifold, then there would have to be a void that could divide it (and he did not believe the void exists). Finally, he stated that the all encompassing Unity is unchanging, for the Unity already encompasses all that is and can be.
Democritus accepted most of Parmenides' arguments, except for the idea that change is an illusion. He believed change was real, and if it was not then at least the illusion had to be explained. He thus supported the concept of void, and stated that the universe is made up of many Parmenidean entities that move around in the void. 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 organisms feel, see, eat, hear, smell, and taste. While organisms may feel hot or cold, hot and cold actually have no real existence. They are simply sensations produced in organisms by the different packings and scatterings of the atoms in the void that compose the object that organisms sense as being "hot" or "cold".
The work of Democritus only survives in secondhand reports, some of which are unreliable or conflicting. Much of the best evidence of Democritus' theory of atomism is reported by Aristotle in his discussions of Democritus' and Plato's contrasting views on the types of indivisibles composing the natural world.
|Element||Polyhedron||Number of Faces||Number of Triangles|
|Geometrical simple bodies according to Plato|
Plato (c. 427 – c. 347 BCE), if he had been familiar with the atomism of Democritus, would have objected to its mechanistic materialism. He argued that atoms just crashing into other atoms could never produce the beauty and form of the world. In Plato's Timaeus (28b–29a) the character of Timeaus 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 four simple bodies of fire, air, water, and earth. But Plato did not consider these corpuscles 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. These simple bodies 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 simple bodies of the four elements as summarized in the adjacent table. 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 the simple bodies 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.
Sometime before 330 BCE 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 in ancient Greece the atomic theories of Democritus remained "pure speculations, incapable of being put to any experimental test. Granted that atomism was, in the long run, to prove far more fruitful than any qualitative theory of matter, in the short run the theory that Aristotle proposed must have seemed in some respects more promising".
Minima naturalia were theorized by Aristotle as the smallest parts into which a homogeneous natural substance (e.g., flesh, bone, or wood) could be divided and still retain its essential character. Unlike the atomism of Democritus, the Aristotelian "natural minimum" was not conceptualized as physically indivisible. Instead, the concept was rooted in Aristotle's hylomorphic worldview, which held that every physical thing is a compound of matter (Greek hyle) and an immaterial substantial form (Greek morphe) that imparts its essential nature and structure. For instance, a rubber ball for a hylomorphist like Aristotle would be rubber (matter) structured by spherical shape (form). Aristotle's intuition was that there is some smallest size beyond which matter could no longer be structured as flesh, or bone, or wood, or some other such organic substance that for Aristotle, living before the microscope, could be considered homogeneous. For instance, if flesh were divided beyond its natural minimum, what would be left might be a large amount of the element water, and smaller amounts of the other elements. But whatever water or other elements were left, they would no longer have the "nature" of flesh: in hylomorphic terms, they would no longer be matter structured by the form of flesh; instead the remaining water, e.g., would be matter structured by the form of water, not the form of flesh.
Epicurus (341–270 BCE) 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' writings survive and those that do reflect his interest in applying Democritus' 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. He understood gods' role as moral ideals.
His ideas are also represented in the works of his follower Lucretius, who wrote On the Nature of Things. This scientific work in poetic form illustrates several segments of Epicurean theory on how the universe came into its current stage and it shows that the phenomena we perceive are actually composite forms. The atoms and the void are eternal and in constant motion. Atomic collisions create objects, which are still composed of the same eternal atoms whose motion for a while is incorporated into the created entity. Human sensations and meteorological phenomena are also explained by Lucretius in terms of atomic motion.
Some later philosophers attributed the idea that man created gods and that gods did not create man to Democritus. For example, Sextus Empiricus noted:
Three hundred years after Epicurus, Lucretius in his epic poem On the Nature of Things would depict him 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 a non-aggressive attitude characterized by his 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." 
In ancient Indian philosophy, preliminary instances of atomism are found in the works of Vedic sage Aruni, who lived in the 8th century BCE, especially his proposition that "particles too small to be seen mass together into the substances and objects of experience". Later, the Charvaka, Jain, and Ajivika schools of atomism originated as early as the 7th century BCE. Bhattacharya posits that Charvaka may have been one of several atheistic, materialist schools that existed in ancient India. The Nyaya and Vaisheshika schools later developed theories on how atoms combined into more complex objects.
Several of these doctrines of atomism are, in some respects, "suggestively similar" to that of Democritus. McEvilley (2002) assumes that such similarities are due to extensive cultural contact and diffusion, probably in either direction.
The Nyaya–Vaisesika school developed one of the earliest forms of atomism; scholars date the Nyaya and Vaisesika texts from the 6th to 1st centuries BC. Vaisesika atomists posited the four elemental atom types, but in Vaisesika physics atoms had 25 different possible qualities, divided between general 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.
The Buddhist atomists had very qualitative, Aristotelian-style atomic theory. According to ancient Buddhist atomism, which probably began developing before the 4th century BCE, 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.
Some of canonical texts of Jainism make reference to matter and atoms (called paramāṇu, a term already used in Yajnavalkya and Yoga Sutra), including Pancastikayasara, Kalpasutra and Tattvarthasutra. The Jains envisioned the world as consisting wholly of atoms, except for souls. Atoms were considered as the basic building blocks of all matter. Each atom had "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. The texts also give "detailed theories" of how atoms could combine, react, vibrate, move, and perform other actions, all of which were thoroughly deterministic.
Medieval Buddhist atomism, flourishing in ca. the 7th century, was very different from the atomist doctrines taught in early Samkhya Buddhism. Medieval Buddhist philosophers Dharmakirti and Dignāga considered atoms to be point-sized, durationless, and made of energy. In discussing the two systems, Fyodor Shcherbatskoy (1930) stresses their commonality, the postulate of "absolute qualities" (guna-dharma) underlying all empirical phenomena.
Still later, the Abhidhammattha-sangaha, a text dated to the 11th or 12th century, postulates the existence of rupa-kalapa, imagined as the smallest units of the physical world, of varying elementary composition. Invisible under normal circumstances, the rupa-kalapa are said to become visible as a result of meditative samadhi.
Atomistic philosophies are found very early in Islamic philosophy and was influenced by earlier Greek and to some extent Indian philosophy. Like both the Greek and Indian versions, Islamic atomism was a charged topic that had the potential for conflict with the prevalent religious orthodoxy, but it was instead more often favoured by orthodox Islamic theologians. It was such a fertile and flexible idea that, as in Greece and India, it flourished in some leading schools of Islamic thought.
The most successful form of Islamic atomism was in the Asharite school of Islamic theology, most notably in the work of the theologian 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). Al-Ghazali also used the theory to support his theory of occasionalism. In a sense, the Asharite theory of atomism has far more in common with Indian atomism than it does with Greek atomism.
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 Al-Andalus, including the noted commentator Averroes (1126–1198 CE) 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 became very influential in Jewish and Christian scholastic thought.
While Aristotelian philosophy eclipsed the importance of the atomists in late Roman and medieval Europe, their work was still preserved and exposited through commentaries on the works of Aristotle. In the 2nd century, Galen (AD 129–216) presented extensive discussions of the Greek atomists, especially Epicurus, in his Aristotle commentaries. 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 17th 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, although the ancient atomists' works were unavailable, Scholastic thinkers still had Aristotle's critiques of atomism. In medieval universities there were expressions of atomism. For example, in the 14th century Nicholas of Autrecourt considered that matter, space, and time were all made up of indivisible atoms, points, and instants and that all generation and corruption took place by the rearrangement of material atoms. The similarities of his ideas with those of al-Ghazali suggest that Nicholas may have been familiar with Ghazali's work, perhaps through Averroes' refutation of it (Marmara, 1973–74).
Although the atomism of Epicurus had fallen out of favor in the centuries of Scholasticism, the minima naturalia of Aristotelianism received extensive consideration. Speculation on minima naturalia provided philosophical background for the mechanistic philosophy of early modern thinkers such as Descartes, and for the alchemical works of Geber and Daniel Sennert, who in turn influenced the corpuscularian alchemist Robert Boyle, one of the founders of modern chemistry.
A chief theme in late Roman and Scholastic commentary on this concept is reconciling minima naturalia with the general Aristotelian principle of infinite divisibility. Commentators like John Philoponus and Thomas Aquinas reconciled these aspects of Aristotle's thought by distinguishing between mathematical and "natural" divisibility. With few exceptions, much of the curriculum in the universities of Europe was based on such Aristotelianism for most of the Middle Ages.
In the 17th century, a renewed interest arose in Epicurean atomism and corpuscularianism as a hybrid or an alternative to Aristotelian physics. The main figures in the rebirth of atomism were René Descartes, Pierre Gassendi, and Robert Boyle, as well as other notable figures.
One of the first groups of atomists in England was a cadre of amateur scientists known as the Northumberland circle, led by Henry Percy, 9th Earl of Northumberland (1564–1632). 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 was 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).
Galileo Galilei (1564–1642) was an advocate of atomism in his 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 identified some basic problems with Aristotelian physics through his experiments. 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. The current Aristotelian theories of impetus and terrestrial motion were inadequate to explain these. While atomism did not explain the law of fall either, it was a more promising framework in which to develop an explanation because motion was conserved in ancient atomism (unlike Aristotelian physics).
René Descartes' (1596–1650) "mechanical" philosophy of corpuscularism had much in common with atomism, and is considered, in some senses, to be a different version of it. Descartes thought everything physical in the universe to be made of tiny vortices 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 Descartes' concept was the existence of the void. For him, 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' view and classical atomism is the mind/body duality of Descartes, which allowed for an independent realm of existence for thought, soul, and most importantly, God. Gassendi's concept was closer to classical atomism, but with no atheistic overtone.
Pierre Gassendi (1592–1655) 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).
Johann Chrysostom Magnenus (c. 1590 – c. 1679) published his Democritus reviviscens in 1646. Magnenus was the first to arrive at a scientific estimate of the size of an "atom" (i.e. of what would today be called a molecule). Measuring how much incense had to be burned before it could be smelled everywhere in a large church, he calculated the number of molecules in a grain of incense to be of the order 1018, only about one order of magnitude below the actual figure.
Corpuscularianism is similar to atomism, except that where atoms were supposed to be indivisible, corpuscles could in principle be divided. In this manner, for example, it was theorized that mercury could penetrate into metals and modify their inner structure, a step on the way towards transmutative production of gold. Corpuscularianism was associated by its leading proponents with the idea that some of the properties that objects appear to have are artifacts of the perceiving mind: 'secondary' qualities as distinguished from 'primary' qualities. Not all corpuscularianism made use of the primary-secondary quality distinction, however. An influential tradition in medieval and early modern alchemy argued that chemical analysis revealed the existence of robust corpuscles that retained their identity in chemical compounds (to use the modern term). William R. Newman has dubbed this approach to matter theory "chymical atomism," and has argued for its significance to both the mechanical philosophy and to the chemical atomism that emerged in the early 19th century. Corpuscularianism stayed a dominant theory over the next several hundred years and retained its links with alchemy in the work of scientists such as Robert Boyle and Isaac Newton in the 17th century. It was used by Newton, for instance, in his development of the corpuscular theory of light. The form that came to be accepted by most English scientists after Robert Boyle (1627–1692) was an amalgam of the systems of Descartes and Gassendi. In The Sceptical Chymist (1661), Boyle demonstrates problems that arise from chemistry, and offers up atomism as a possible explanation. The unifying principle that would eventually lead to the acceptance of a hybrid corpuscular–atomism was mechanical philosophy, which became widely accepted by physical sciences.
By the late 18th century, 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.
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.
And then he proceeded to give a list of relative weights in the compositions of several common compounds, summarizing:
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.
Dalton's atomic theory remained controversial throughout the 19th century. Whilst the Law of definite proportion was accepted, the hypothesis that this was due to atoms was not so widely accepted. For example, in 1826 when Sir Humphry Davy presented Dalton the Royal Medal from the Royal Society, Davy said that the theory only became useful when the atomic conjecture was ignored. Sir Benjamin Collins Brodie in 1866 published the first part of his Calculus of Chemical Operations as a non-atomic alternative to the Atomic Theory. He described atomic theory as a 'Thoroughly materialistic bit of joiners work'. Alexander Williamson used his Presidential Address to the London Chemical Society in 1869 to defend the Atomic Theory against its critics and doubters. This in turn led to further meetings at which the positivists again attacked the supposition that there were atoms. The matter was finally resolved in Dalton's favour in the early 20th century with the rise of atomic physics.
Atoms and molecules had long been theorized as the constituents of matter, and Albert Einstein published a paper in 1905 that explained in precise detail how the motion that Brown had observed was a result of the pollen being moved by individual water molecules, making one of his first big contributions to science. This explanation of Brownian motion served as convincing evidence that atoms and molecules exist, and was further verified experimentally by Jean Perrin in 1908. Perrin was awarded the Nobel Prize in Physics in 1926 "for his work on the discontinuous structure of matter". The direction of the force of atomic bombardment is constantly changing, and at different times the particle is hit more on one side than another, leading to the seemingly random nature of the motion.
Andrew Pyle (born 17 March 1955) is a British philosopher on the history of philosophical atomism.
Pyle is currently a Reader in Early Modern Philosophy at the University of Bristol, where he also received his doctorate. His dissertation was titled Atomism and its Critics: Democritus to Newton. Pyle also writes on the history of science and has given talks within the university on the nature of science historically. Pyle is one of the editors of the Continuum Encyclopedia of British Philosophy.In 2018, Bristol University held an all day conference honouring the thematic themes of Pyle's researchAtomic theory
In chemistry and physics, atomic theory is a scientific theory of the nature of matter, which states that matter is composed of discrete units called atoms. It began as a philosophical concept in ancient Greece and entered the scientific mainstream in the early 19th century when discoveries in the field of chemistry showed that matter did indeed behave as if it were made up of atoms.
The word atom comes from the Ancient Greek adjective atomos, meaning "indivisible". 19th century chemists began using the term in connection with the growing number of irreducible chemical elements. Around the turn of the 20th century, through various experiments with electromagnetism and radioactivity, physicists discovered that the so-called "uncuttable atom" was actually a conglomerate of various subatomic particles (chiefly, electrons, protons and neutrons) which can exist separately from each other. In fact, in certain extreme environments, such as neutron stars, extreme temperature and pressure prevents atoms from existing at all.
Since atoms were found to be divisible, physicists later invented the term "elementary particles" to describe the "uncuttable", though not indestructible, parts of an atom. The field of science which studies subatomic particles is particle physics, and it is in this field that physicists hope to discover the true fundamental nature of matter.Buddhist atomism
Buddhist atomism is a school of atomistic Buddhist philosophy that flourished on the Indian subcontinent during two major periods. During the first phase, which began to develop prior to the 6th century BCE, Buddhist atomism had a very qualitative, Aristotelian-style atomic theory. This form of atomism identifies 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 Hindus and Jains, the Buddhists were able to integrate a theory of atomism with their logical presuppositions.
According to Noa Ronkin, this kind of atomism was developed in the Sarvastivada and Sautrantika schools for whom material reality can be: reduced to discrete momentary atoms, namely, the four primary elements. These momentary atoms, through their spatial arrangement and by their concatenation with prior and posterior atoms of the same type, create the illusion of persisting things as they appear in our everyday experience. Atomic reality is thus understood first and foremost as change, though not in the sense of a thing x transforming into y. That is, change itself is the very nature of atomic reality rather than its being made of enduring substances the qualities of which undergo change. Atoms that appear to endure are, in fact, a series of momentary events that ascend and fall in rapid succession and in accordance with causal relations. Unlike the atoms of the Vaifesika, the atoms of the Sarvastivada-Vaibhasika and the Sautrantika are not permanent: they come into being and cease from one moment to the next going through a process of birth, continuance, decay and destruction. Yet the material compounds that consist of these atoms are real, if only in the minimal, phenomenological sense.The second phase of Buddhist atomism, which flourished in the 7th century CE, was very different from the first. Indian Buddhist philosophers, including Dharmakirti and Dignāga, considered atoms to be point-sized, durationless, and made of energy. In discussing Buddhist atomism, Stcherbatsky writes:
... The Buddhists denied the existence of substantial matter altogether. Movement consists for them of moments, it is a staccato movement, momentary flashes of a stream of energy... "Everything is evanescent," ... says the Buddhist, because there is no stuff ... Both systems [Sānkhya and later Indian Buddhism] share in common a tendency to push the analysis of Existence up to its minutest, last elements which are imagined as absolute qualities, or things possessing only one unique quality. They are called "qualities" (guna-dharma) in both systems in the sense of absolute qualities, a kind of atomic, or intra-atomic, energies of which the empirical things are composed. Both systems, therefore, agree in denying the objective reality of the categories of Substance and Quality, ... and of the relation of Inference uniting them. There is in Sānkhya philosophy no separate existence of qualities. What we call quality is but a particular manifestation of a subtle entity. To every new unit of quality corresponds a subtle quantum of matter which is called guna "quality", but represents a subtle substantive entity. The same applies to early Buddhism where all qualities are substantive ... or, more precisely, dynamic entities, although they are also called dharmas ("qualities").Clinamen
Clinamen (; plural clinamina, derived from clīnāre, to incline) is the Latin name Lucretius gave to the unpredictable swerve of atoms, in order to defend the atomistic doctrine of Epicurus. In modern English it has come more generally to mean an inclination or a bias.Corpuscular theory of light
In optics, the corpuscular theory of light, arguably set forward by Descartes (1637) states that light is made up of small discrete particles called "corpuscles" (little particles) which travel in a straight line with a finite velocity and possess impetus. This was based on an alternate description of atomism of the time period. This theory cannot explain refraction, diffraction, interference and polarization.
Isaac Newton was a pioneer of this theory, in 1672.Corpuscularianism
Corpuscularianism is a physical theory that supposes all matter to be composed of minute particles. The theory became important in the seventeenth century; amongst the leading corpuscularians were Thomas Hobbes, René Descartes, Pierre Gassendi, Robert Boyle, Isaac Newton, and John Locke.Dravya
Dravya (Hindi: द्रव्य) is a term used to refer to a substance. According to the Jain philosophy, the universe is made up of six eternal substances: sentient beings or souls (jīva), non-sentient substance or matter (pudgala), principle of motion (dharma), the principle of rest (adharma), space (ākāśa) and time (kāla). The latter five are united as the ajiva (the non-living). As per the Sanskrit etymology, dravya means substances or entity, but it may also mean real or fundamental categories.Jain philosophers distinguish a substance from a body, or thing, by declaring the former as a simple element or reality while the latter as a compound of one or more substances or atoms. They claim that there can be a partial or total destruction of a body or thing, but no substance can ever be destroyed.Kalpa Sūtra
The Kalpa Sūtra (Sanskrit: कल्पसूत्र) is a Jain text containing the biographies of the Jain Tirthankaras, notably Parshvanatha and Mahavira. Traditionally ascribed to Bhadrabahu, which would place it in the 4th century BCE., it was probably put to writing only after 980 or 993 years after the Nirvana(Moksha) of Mahavira.Leucippus
Leucippus (; Greek: Λεύκιππος, Leúkippos; fl. 5th cent. BCE) is reported in some ancient sources to have been a philosopher who was the earliest Greek to develop the theory of atomism—the idea that everything is composed entirely of various imperishable, indivisible elements called atoms. Leucippus often appears as the master to his pupil Democritus, a philosopher also touted as the originator of the atomic theory. However, a brief notice in Diogenes Laërtius’s life of Epicurus says that on the testimony of Epicurus, Leucippus never existed. As the philosophical heir of Democritus, Epicurus's word has some weight, and indeed a controversy over this matter raged in German scholarship for many years at the close of the 19th century. Furthermore, in his Corpus Democriteum, Thrasyllus of Alexandria, an astrologer and writer living under the emperor Tiberius (14–37 CE), compiled a list of writings on atomism that he attributed to Democritus to the exclusion of Leucippus. The present consensus among the world's historians of philosophy is that this Leucippus is historical. The matter must remain moot unless more information is forthcoming from the record.
Leucippus was most likely born in Miletus, although Abdera and Elea are also mentioned as possible birthplaces.Logical atomism
Logical atomism is a philosophy that originated in the early 20th century with the development of analytic philosophy. Its principal exponent was the British philosopher Bertrand Russell. It is also widely held that the early work (the Tractatus and pre-Tractatus writings) of his Austrian-born pupil and colleague, Ludwig Wittgenstein, defend a version of logical atomism. Some philosophers in the Vienna Circle were also influenced by logical atomism. Rudolf Carnap was also deeply sympathetic to some of the philosophical aims of logical atomism. Gustav Bergmann also developed a form of logical atomism that focused on an ideal phenomalistic language, particularly in his discussions of J.O. Urmson's work on analysis.The name for this kind of theory was coined in March 1911 by Russell, in a work published in French titled "Le Réalisme analytique" (published in translation as "Analytic Realism" in Volume 6 of The Collected Papers of Bertrand Russell). Russell was developing and responding to what he called "logical holism"—i.e., the belief that the world operates in such a way that no part can be known without the whole being known first. This belief is commonly called monism, and Russell (and G. E. Moore) criticized the absolute idealism dominant then in Britain and exemplified in works of F. H. Bradley and J. M. E. McTaggart. Logical atomism is partly understood as a developed alternative to logical holism, or the "monistic logic" of Idealists, on which logical analysis is a kind of falsification.
The theory holds that the world consists of ultimate logical "facts" (or "atoms") that cannot be broken down any further. Having originally propounded this stance in his Tractatus Logico-Philosophicus, Wittgenstein rejected it in his later Philosophical Investigations (§§46–49, §81, §91).Lucretius
Titus Lucretius Carus (; c. 15 October 99 BC – c. 55 BC) was a Roman poet and philosopher. His only known work is the philosophical poem De rerum natura, a didactic work about the tenets and philosophy of Epicureanism, and which is usually translated into English as On the Nature of Things. Lucretius has been credited with originating the concept of the three-age system which was formalised from 1834 by C. J. Thomsen.
Very little is known about Lucretius's life; the only certain fact is that he was either a friend or client of Gaius Memmius, to whom the poem was addressed and dedicated.De rerum natura was a considerable influence on the Augustan poets, particularly Virgil (in his Aeneid and Georgics, and to a lesser extent on the Eclogues) and Horace. The work virtually disappeared during the Middle Ages, but was rediscovered in 1417 in a monastery in Germany by Poggio Bracciolini and it played an important role both in the development of atomism (Lucretius was an important influence on Pierre Gassendi) and the efforts of various figures of the Enlightenment era to construct a new Christian humanism.Materialism
Materialism is a form of philosophical monism which holds that matter is the fundamental substance in nature, and that all things, including mental aspects and consciousness, are results of material interactions.
In Idealism, mind and consciousness are first-order realities to which matter is subject and secondary. In philosophical materialism the converse is true. Here mind and consciousness are by-products or epiphenomena of material processes (the biochemistry of the human brain and nervous system, for example) without which they cannot exist. According to this doctrine the material creates and determines consciousness, not vice versa.
Materialist theories are mainly divided into three groups. Naive materialism identifies the material world with specific elements (e.g. the scheme of the four elements—fire, air, water and earth—devised by the pre-Socratic philosopher Empedocles). Metaphysical materialism examines separated parts of the world in a static, isolated environment. Dialectical materialism adapts the Hegelian dialectic for materialism, examining parts of the world in relation to each other within a dynamic environment.
Materialism is closely related to physicalism, the view that all that exists is ultimately physical. Philosophical physicalism has evolved from materialism with the discoveries of the physical sciences to incorporate more sophisticated notions of physicality than mere ordinary matter, such as: spacetime, physical energies and forces, dark matter, and so on. Thus the term "physicalism" is preferred over "materialism" by some, while others use the terms as if they are synonymous.
Philosophies contradictory to materialism or physicalism include idealism, pluralism, dualism, and other forms of monism.Minima naturalia
Minima naturalia ("natural minima") were theorized by Aristotle as the smallest parts into which a homogeneous natural substance (e.g., flesh, bone, or wood) could be divided and still retain its essential character. In this context, "nature" means formal nature. Thus, "natural minimum" may be taken to mean "formal minimum": the minimum amount of matter necessary to instantiate a certain form.
Speculation on minima naturalia in late Antiquity, in the Islamic world, and by Scholastic and Renaissance thinkers in Europe provided a conceptual bridge between the atomism of ancient Greece and the mechanistic philosophy of early modern thinkers like Descartes, which in turn provided a background for the rigorously mathematical and experimental atomism of modern science.Pancastikayasara
Pañcastikayasara (en: the essence of reality), is an ancient Jain text authored by Acharya Kundakunda. Kundakunda explains the Jain concepts of dravya (substance) and Ethics. The work serves as a brief version of the Jaina philosophy. There are total 180 verses written in Prakrit language. The text is about five (panch) āstikāya, substances that have both characteristics, viz. existence as well as body.Tattvartha Sutra
Tattvartha Sutra (also known as Tattvarth-adhigama-sutra) is an ancient Jain text written by Acharya Umaswati, sometime between the 2nd- and 5th-century AD. It is the one of the Jain scripture written in the Sanskrit language. Tattvartha Sutra is also known in Jainism as the Moksha-shastra (Scripture describing the path of liberation).
The Tattvartha Sutra is regarded as one of the earliest, most authoritative text in Jainism, and the only text authoritative in both the Digambara and Śvētāmbara sects. Its importance in Jainism is comparable with that of the Brahma Sutras and Yoga Sutras of Patanjali in Hinduism. It is a text in sutra or aphorisms, and presents the complete Jainism philosophy in 350 sutras over 10 chapters. The term Tattvartha is composed of the Sanskrit words tattva which means "reality, truth" and artha which means "nature, meaning", together meaning "nature of reality".One of its sutras, Parasparopagraho Jivanam is the motto of Jainism. Its meaning is interpreted as "(The function) of souls is to help one another", or "Souls render service to one another".Tractatus Logico-Philosophicus
The Tractatus Logico-Philosophicus (widely abbreviated and cited as TLP) (Latin for Logical Philosophical Treatise or Treatise on Logic and Philosophy) is the only book-length philosophical work by the Austrian philosopher Ludwig Wittgenstein that was published during his lifetime. The project had a broad goal: to identify the relationship between language and reality and to define the limits of science. It is recognized by philosophers as a significant philosophical work of the twentieth century. G. E. Moore originally suggested the work's Latin title as homage to the Tractatus Theologico-Politicus by Baruch Spinoza.Wittgenstein wrote the notes for the Tractatus while he was a soldier during World War I and completed it during a military leave in the summer of 1918. It was first published in German in 1921 as Logisch-Philosophische Abhandlung. The Tractatus was influential chiefly amongst the logical positivist philosophers of the Vienna Circle, such as Rudolf Carnap and Friedrich Waismann. Bertrand Russell's article "The Philosophy of Logical Atomism" is presented as a working out of ideas that he had learned from Wittgenstein.The Tractatus employs an austere and succinct literary style. The work contains almost no arguments as such, but rather consists of declarative statements, or passages, that are meant to be self-evident. The statements are hierarchically numbered, with seven basic propositions at the primary level (numbered 1–7), with each sub-level being a comment on or elaboration of the statement at the next higher level (e.g., 1, 1.1, 1.11, 1.12, 1.13). In all, the Tractatus comprises 526 numbered statements.
Wittgenstein's later works, notably the posthumously published Philosophical Investigations, criticised many of his earlier ideas in the Tractatus.Vaisheshika
Vaisheshika or Vaiśeṣika (Sanskrit: वैशेषिक) is one of the six orthodox schools of Hindu philosophy (Vedic systems) from ancient India. In its early stages, the Vaiśeṣika was an independent philosophy with its own metaphysics, epistemology, logic, ethics, and soteriology. Over time, the Vaiśeṣika system became similar in its philosophical procedures, ethical conclusions and soteriology to the Nyāya school of Hinduism, but retained its difference in epistemology and metaphysics.
The epistemology of Vaiśeṣika school of Hinduism, like Buddhism, accepted only two reliable means to knowledge: perception and inference. Vaiśeṣika school and Buddhism both consider their respective scriptures as indisputable and valid means to knowledge, the difference being that the scriptures held to be a valid and reliable source by Vaiśeṣikas were the Vedas.
Vaisheshika school is known for its insights in naturalism. It is a form of atomism in natural philosophy. It postulated that all objects in the physical universe are reducible to paramāṇu (atoms), and one's experiences are derived from the interplay of substance (a function of atoms, their number and their spatial arrangements), quality, activity, commonness, particularity and inherence. According to Vaiśeṣika school, knowledge and liberation were achievable by a complete understanding of the world of experience.Vaiśeṣika darshana was founded by Kaṇāda Kashyapa around the 6th to 2nd century BC.Vaiśeṣika Sūtra
Vaiśeṣika Sūtra, (Sanskrit: वैशेषिक सूत्र), also called Kanada sutra, is an ancient Sanskrit text at the foundation of the Vaisheshika school of Hindu philosophy. The sutra was authored by the Hindu sage Kanada, also known as Kashyapa. According to some scholars, he flourished before the advent of Buddhism because the Vaiśeṣika Sūtra makes no mention of Buddhism or Buddhist doctrines; however, the details of Kanada's life are uncertain, and the Vaiśeṣika Sūtra was likely compiled sometime between 6th and 2nd century BCE, and finalized in the currently existing version before the start of the common era.A number of scholars have commented on it since the beginning of common era; the earliest commentary known is the Padartha Dharma Sangraha of Prashastapada. Another important secondary work on Vaiśeṣika Sūtra is Maticandra's Dasha padartha sastra which exists both in Sanskrit and its Chinese translation in 648 CE by Yuanzhuang.The Vaiśeṣika Sūtra is written in aphoristic sutras style, and presents its theories on the creation and existence of the universe using naturalistic atomism, applying logic and realism, and is one of the earliest known systematic realist ontology in human history. The text discusses motions of different kind and laws that govern it, the meaning of dharma, a theory of epistemology, the basis of Atman (self, soul), and the nature of yoga and moksha. The explicit mention of motion as the cause of all phenomena in the world and several propositions about it make it one of the earliest texts on physics.Ājīvika
Ajivika (IAST: Ājīvika) is one of the nāstika or "heterodox" schools of Indian philosophy. Purportedly founded in the 5th century BCE by Makkhali Gosala, it was a śramaṇa movement and a major rival of vedic religion, early Buddhism and Jainism. Ājīvikas were organised renunciates who formed discrete communities.Original scriptures of the Ājīvika school of philosophy may once have existed, but these are currently unavailable and probably lost. Their theories are extracted from mentions of Ajivikas in the secondary sources of ancient Indian literature. Scholars question whether Ājīvika philosophy has been fairly and completely summarized in these secondary sources, as they were written by groups (such as the Buddhists and Jains) competing with and adversarial to the philosophy and religious practices of the Ajivikas. It is therefore likely that much of the information available about the Ājīvikas is inaccurate to some degree, and characterisations of them should be regarded carefully and critically.
The Ājīvika school is known for its Niyati ("Fate") doctrine of absolute determinism, the premise that there is no free will, that everything that has happened, is happening and will happen is entirely preordained and a function of cosmic principles. Ājīvikas considered the karma doctrine as a fallacy. Ajivika metaphysics included a theory of atoms which was later adapted in Vaisheshika school, where everything was composed of atoms, qualities emerged from aggregates of atoms, but the aggregation and nature of these atoms was predetermined by cosmic forces. Ājīvikas were considered as atheists. They believed that in every living being is an ātman – a central premise of Hinduism and Jainism.Founded in what is now the northern Indian state of Uttar Pradesh, Ājīvika philosophy reached the height of its popularity during the rule of the Mauryan emperor Bindusara, around the 4th century BCE. This school of thought thereafter declined, but survived for nearly 2,000 years through the 14th century CE in the southern Indian states of Karnataka and Tamil Nadu. The Ājīvika philosophy, along with the Cārvāka philosophy, appealed most to the warrior, industrial and mercantile classes of ancient Indian society.