God, self, and body.
In the Yoga-sutras, God is defined as a distinct self (purusa), untouched by sufferings, actions, and their effects; his existence is proved on the ground that the degrees of knowledge found in finite beings, in an ascending order, has an upper limit--i.e., omniscience, which is what characterizes God. He is said to be the source of all secular and scriptural traditions; he both revealed the Vedas and taught the first fathers of mankind. Surrender of the effects of action to God is regarded as a recommended observance.

As in Samkhya, the self is distinguished from the mind (citta): the mind is viewed as an object, an aggregate. This argument is used to prove the existence of a self other than the mind. The mental state is not self-intimating; it is known in introspection. It cannot know both itself and its object. It rather is known by the self, whose essence is pure, undefiled consciousness. That the self is not changeable is proved by the fact that were it changeable the mental states would be sometimes known and sometimes unknown--which, however, is not the case, because a mental state is always known. To say that the self knows means that the self is reflected in the mental state and makes the latter manifested. The aim of Yoga is to arrest mental modifications (citta-vrtti) so that the self remains in its true, undefiled essence and is, thus, not subject to suffering.

 The attitude of the Yoga-sutras to the human body is ambivalent. The body is said to be filthy and unclean. Thus, the ascetic cultivates a disgust for it. Yet, much of the discipline laid down in the Yoga-sutras concerns perfection of the body, with the intent to make it a fit instrument for spiritual perfection. Steadiness in bodily posture and control of the breathing process are accorded a high place. The perfection of body is said to consist in "beauty, grace, strength and adamantine hardness."

Theories and techniques of self-control and meditation.
Patanjali lays down an eightfold path consisting of aids to Yoga: restraint (yama), observance (niyama), posture (asana), regulation of breathing (pranayama), abstraction of the senses (pratyahara), concentration (dharana), meditation (dhyana), and trance (samadhi). The first two constitute the ethical core of the discipline: the restraints are abstinence from injury, veracity, abstinence from stealing, continence, and abstinence from greed. The observances are cleanliness, contentment, purificatory actions, study, and surrender of the fruits of one's actions to God. Ahimsa (nonviolence) also is glorified, as an ethics of detachment.

 Various stages of samadhi are distinguished: the conscious and the superconscious, which are subdivided into achievements with different shades of perfection. In the final stage, all mental modifications cease to be and the self is left in its pure, undefiled state of utter isolation. This is freedom (kaivalya), or absolute independence.
 
 

Organization and contents.
The Vaishesika-sutras are divided into ten chapters, each with two sections. Chapter 1 states the purpose of the work: to explain dharma, defined as that which confers prosperity and ultimate good on man. This is followed by an enumeration of the categories of being recognized in the system: substance, quality (guna), action, universality, particularity, and inherence (samavaya). Later authors add a seventh category: negation (abhava). This enumeration is followed by an account of the common features as well as dissimilarities among these categories: the categories of "universal" and "particularity" and the concepts of being and existence. Chapter 2 classifies substances into nine kinds: earth, water, fire, air, ether, space, time, self, and mind. There next follows a discussion of the question of whether sound is eternal or noneternal. Chapter 3 is an attempt to prove the existence of self by an inference. Chapter 4 explains the words "eternal" and "noneternal," the noneternal being identified with avidya, and distinguishes between three different forms of the substances earth, water, fire, and air--each of these is either a body, a sense organ, or an object. Chapter 5 deals with the notion of action and the connected concept of effort, and the next traces various special phenomena of nature to the supersensible force, called adrsta. Chapter 6 argues that performance of Vedic injunctions generates this supersensible force and that the merits and demerits accumulated lead to moksa. Chapter 7 argues that qualities of eternal things are eternal and those of noneternal things are noneternal. Chapter 8 argues that the self and mind are not perceptible. Chapter 9 argues that neither action nor qualities may be ascribed to what is nonexistent and, further, that negation may be directly perceived. Chapter 9 also deals with the nature of hetu, or the "middle term" in syllogism, and argues that the knowledge derived from hearing words is not inferential. Chapter 10 argues that pleasure and pain are not cognitions because they do not leave room for either doubt or certainty.

Structure of the world.
This account of the contents of the sutras shows that the Vaishesika advocates an atomistic cosmology (theory of order) and a pluralistic ontology (theory of being). The material universe arises out of the conjunction of four kinds of atoms: the earth atom, water atom, fire atom, and air atom. There also are the eternal substances: ether, in which sound inheres as a quality; space, which accounts for man's sense of direction and distinctions between far and near; and time, which accounts for the notions of simultaneity and nonsimultaneity and which, like space, is eternal and is the general cause of all that has origin.

Naturalism.
The overall naturalism of the Vaishesika, its great interest in physics, and its atomism are all counterbalanced by the appeal to adrsta (a supersensible force), to account for whatever the other recognized entities cannot explain. Among things ascribed to this supersensible force are movements of needles toward a magnet, circulation of water in plant bodies, upward motion of fire, movement of mind, and movements of soul after death. These limit the naturalism of the system.

Epistemology.
Knowledge belongs to the self; it appears or disappears with the contact of the self with the senses and of the senses with the objects. Perception of the self results from the conjunction of the self with the mind. Perception of objects results from proximity of the self, the senses, and the objects. Error exists because of defects of the senses. Inference is of three kinds: inference of the nonexistence of something from the existence of some other things, inference of the existence of something from nonexistence of some other, and inference of existence of something from the existence of some other thing.

Ethics.
Moksa is a state in which there is no body and no rebirth. It is achieved by knowledge. Works in accordance with the Vedic injunction may help in its attainment.
 
 

Content and organization.
The sutras are divided into five chapters, each with two sections. The work begins with a statement of the subject matter, purpose, and relation of the subject matter to the attainment of that purpose. The ultimate purpose is salvation--i.e., complete freedom from pain--and salvation is attained by knowledge of the 16 categories: hence the concern with these categories, which are means of valid knowledge (pramana); objects of valid knowledge (prameya); doubt (samshaya); purpose (prayojana); example (drstanta); conclusion (siddhanta); the constituents of a syllogism (avayava); argumentation (tarka); ascertainment (nirnaya); debate (vada); disputations ( jalpa); destructive criticism (vitanda); fallacy (hetvabhasa); quibble (chala); refutations ( jati); and points of the opponent's defeat (nigrahasthana).

Epistemology.
The words "knowledge," buddhi, and "consciousness" are used synonymously. Four means of valid knowledge are admitted: perception, inference, comparison, and verbal testimony. Perception is defined as the knowledge that arises from the contact of the senses with the object, which is nonjudgmental, or unerring or judgmental. Inference is defined as the knowledge that is preceded by perception (of the mark) and classified into three kinds: that from the perception of a cause to its effect; that from perception of the effect to its cause; and that in which knowledge of one thing is derived from the perception of another with which it is commonly seen together. Comparison is defined as the knowledge of a thing through its similarity to another thing previously well-known.

 The validity of the means of knowing is established as against Buddhist skepticism, the main argument being that if no means of knowledge is valid then the demonstration of their invalidity cannot itself claim validity. Perception is shown to be irreducible to inference, inference is shown to yield certain knowledge, and errors in inference are viewed as being faults in the person, not in the method itself. Knowledge derived from verbal testimony is viewed as noninferential.

Theory of causation and metaphysics.
Although the sutras do not explicitly develop a detailed theory of causation, the later Nyaya theory is sufficiently delineated in Chapter 4. No event is uncaused. No positive entity could arise out of mere absence--a thesis that is pressed against what seems to be a Buddhist view that in a series of momentary events every member is caused by the destruction of the preceding member. Cause and effect should be homogeneous in nature, and yet the effect is a new beginning and was not already contained in the cause. The Buddhist thesis that all things are negative in nature (inasmuch as a thing's nature is constituted by its differences from others) is rejected, as is the view that all things are eternal or that all things are noneternal. Both these latter views are untrue to experience. Thus, the resulting metaphysics admits two kinds of entities: eternal and noneternal. The whole is a new entity over and above the parts that constitute it. Also, the idea that God is the material cause of the universe is rejected. God is viewed as the efficient cause, and human deeds produce their results under the control and cooperation of God.

The syllogism and its predecessors.
Of the four main topics of the Nyaya-sutras (art of debate, means of valid knowledge, syllogism, and examination of opposed views) there is a long history. There is no direct evidence for the theory that though inference (anumana) is of Indian origin, the syllogism (avayava) is of Greek origin. Vatsayana, the commentator on the sutras, referred to some logicians who held a theory of a ten-membered syllogism (the Greeks had three). The Vaishesika-sutras give five propositions as constituting a syllogism but give them different names. Gautama also supports a five-membered syllogism with the following structure:

1. This hill is fiery (pratijna: a statement of that which is to be proved).
2. Because it is smoky (hetu: statement of reason).
3. Whatever is smoky is fiery, as is a kitchen (udaharana: 
statement of a general rule supported by an example).
4. So is this hill (upanaya: application of the rule of this case).
5. Therefore this hill is fiery (nigamana: drawing the conclusion).

The characteristic feature of the Nyaya syllogism is its insistence on the example--which suggests that the Nyaya logician wanted to be assured not only of formal validity but also of material truth. Five kinds of fallacious "middle" (hetu) are distinguished: the inconclusive (savyabhicara), which leads to more conclusions than one; the contradictory (viruddha), which opposes that which is to be established; the controversial (prakaranasama), which provokes the very question that it is meant to settle; the counterquestioned (sadhyasama), which itself is unproved; and the mistimed (kalatita), which is adduced "when the time in which it might hold good does not apply."

Other characteristic philosophic matters.
Other philosophical theses stated in the sutras are as follows: the relation of words to their meanings is not natural but conventional; a word means neither the bare individual nor the universal by itself but all three--the individual, the universal, and structure (akrti); desire, aversion, volition, pleasure, pain, and cognition are the marks of the self; body is defined as the locus of gestures, senses, and sentiments; and the existence and atomicity of mind are inferred from the fact that there do not arise in the self more acts of knowledge than one at a time.
 
 

Contributions of the Mahasangikas.
When the Mahasangikas ("School of the Great Assembly") seceded from the Elders (Theravadins) about 400 BC, the germs were laid for the rise of the Mahayana Buddhism. The Mahasangikas admitted non-arhat monks and worshippers (i.e., those who had not attained perfection), defied the Buddha, taught the doctrine of the emptiness of the elements of being, distinguished between the mundane and the supramundane reality, and considered consciousness (vijnana) to be intrinsically free from all impurities. These ideas found varied expression among the various groups into which the Mahasangikas later divided  ????

Contributions of the Sarvastivadins.
The Sarvastivadins ("realists" who believe that all things, mental and material, exist or also that all dharmas--past, present, and future--exist) seceded from the Elders about the middle of the 3rd century BC. They rejected, in common with all other sects, pudgalatma, or a self of the individual, but admitted dharmatman--i.e., self-existence of the dharmas (categories), or the elements of being. Each dharma is a self-being; the law of causality applies to the formation of aggregates, not to the elements themselves. Dharmas, whether they are past or are in future, exist all the same. Of these, three are said to be unconditioned: space (akasha) and the two cessations (nirodha)--the cessation that arises from knowledge and the cessation that arises prior to the attainment of knowledge, the former being Nirvana, the latter being an arrest of the flow of passions through meditation prior to the achievement of Nirvana. By shunyata the Sarvastivadins mean only the truth that there is no eternal substance called "I." Because all elements--past, present, or future--exist, the Sarvastivadins are obliged to account for these temporal predicates, and several different theories are advanced. Of these, the theory advanced by Vasumitra, a 1st-2nd-century-AD Sarvastivadin, viz., that temporal predicates are determined by the function of a dharma, is accepted by the Vaibhasikas--i.e., those among the Sarvastivadins who follow the authority of the texts known as the Vibhasa.

Contributions of the Sautrantikas.
The Vaibhasika doctrine of eternal elements is believed to be inconsistent with the fundamental teachings of the Buddha. The Sautrantikas (so-called because they rest their case on the sutras) insist on the noneternality of the dharma as well. The past and the future dharmas do not exist, and only the present ones do. The so-called unconditioned dharmas are mere absences, not positive entities. Thus, the Sautrantikas seem to be the only major school of Buddhist philosophy that comes near to regarding Nirvana as entirely negative. In their epistemology, whereas the Vaibhasikas are direct realists, the Sautrantikas hold a sort of representationism, according to which the external world is only inferred from the mental conceptions that alone are directly apprehended.
 
 

Kautilya's Arthashastra (c. 321-296 BC) is the science of artha, or material prosperity, which is one of the four goals of human life. By artha, Kautilya meant "the means of subsistence of man," which is, primarily, wealth and, secondarily, earth. The work is concerned with the means of fruitfully maintaining and using the latter--i.e., land. It is a work on politics and diplomacy.

Theories of kingship and statecraft.
Though Kautilya recognized that sovereignty may belong to a clan (kula), he was himself concerned with monarchies. He advocated the idea of the king's divine nature, or divine sanction of the king's office, but he also attempted to reconcile it with a theory of the elective origin of the king. He referred to a state of nature, without king, as an anarchy in which the stronger devours the weaker. The four functions of the king are to acquire what is not gained, to protect what is gained, to increase what is protected, and to bestow the surplus upon the deserving. The political organization is held to have seven elements: the king, the minister, the territory, the fort, the treasury, the army, and the ally. These are viewed as being organically related. The three "powers" of the king are power of good counsel, the majesty of the king himself, and the power to inspire. The priest is not made an element of the state organization. The king, however, is not exempt from the laws of dharma. Being the "promulgator of dharma," the king should himself be free from the six passions of sex, anger, greed, vanity, haughtiness, and overjoy. What Kautilya advocated was an enlightened monarchical paternalism.

Concepts of the public good.
In the happiness of the subjects lies the king's happiness. The main task of the king is to offer protection. Monarchy is viewed as the only guarantee against anarchy. Thus, the king's duty is to avert providential visitations such as famine, flood, and pestilence; he ought also to protect agriculture, industry, and mining, the orphan, the aged, the sick, and the poor, to control crime with the help of spies, and to settle legal disputes.

Relations between states.
Regarding relations with other states, Kautilya's thoughts were based not so much on high moral idealism as on the needs of self-interest. He wrote of six types of foreign policy: treaty (sandhi), war (vigraha), marching against the enemy (yana), neutrality (asana), seeking protection from a powerful king (samshraya), and dual policy (dvaidhibhava). The rules concerning these are: he who is losing strength in comparison to the other shall make peace; he who is gaining strength shall make war; he who thinks neither he nor the enemy can win shall be neutral; he who has an excess of advantage shall march; he who is wanting in strength shall seek protection; he who undertakes work requiring assistance shall adopt a dual policy.

The formation and implementation of policy.
Kautilya's views about the formation and implementation of policy were as follows: a treaty based on truth and oath is binding for temporal and spiritual consequences; a treaty based on security is binding only as long as the party is strong. He who inflicts severe punishments becomes oppressive; he who inflicts mild punishments is overpowered; and he who inflicts just punishments is respected. Kautilya advocated an elaborate system of espionage for domestic as well as foreign affairs.
 
 

The Ajivikas.
About the time of the rise of Buddhism, there was a sect of religious mendicants, the Ajivikas, who held unorthodox views. In the strict sense, this name is applied to the followers of one Makkhali Gosala, but in a wide sense it is also applied to those who taught many different shades of heretical teachings. Primary sources of knowledge about these are the Digha Nikaya, Anguttara Nikaya, Samyutta Nikaya, the Sutrakrtanga-sutra, Shilanka's commentary on the Sutrakrtanga-sutra, the Bhagavati-sutra, the Nandi-sutra, and Abhayadeva's commentary on Samavayanga-sutra.

 Makkhali's views may be thus summarized. There is no cause of the depravity of things; they become depraved without any reason or cause. There is also no cause of the purity of beings; they become pure without any reason or cause. Nothing depends either on one's own efforts or on the efforts of others. All things are destitute of power, force, or energy. Their changing states are due to destiny, environment, and their own nature. Thus, Makkhali denies sin, or dharma, and denies freedom of man in shaping his own future. He is thus a determinist, although scholars have held the view that he might leave room for chance, if not for freedom of will. He is supposed to have held an atomistic cosmology and that all beings, in the course of time, are destined to culminate in a state of final salvation. He believes not only in rebirth but also in a special doctrine of reanimation according to which it is possible for one person's soul to be reanimated in the dead bodies of others. Thus, the Ajivikas are far from being materialists.

The Carvakas.
Another pre-Buddhistic system of philosophy, the Carvaka, or the Lokayata, is one of the earliest materialistic schools of philosophy.The name Carvaka is traced back to one Carvaka, supposed to have been one of the great teachers of the school. The other name, Lokayata, means "the view held by the common people," "the system which has its base in the common, profane world," "the art of sophistry," and also "the philosophy that denies that there is any world other than this one." Brhaspati probably was the founder of this school. Much knowledge of the Carvakas, however, is derived from the expositions of the later Hindu writings, particularly from Madhava's Sarva-darshana-samgraha ("Compendium of All Philosophies," 14th century). Haribhadra in his Saddarshanasamuccaya ("Compendium of the Six Philosophies," 5th century AD) attributes to the Carvakas the view that this world extends only to the limits of possible sense experience.

 The Carvakas apparently sought to establish their materialism on an epistemological basis. In their epistemology, they viewed sense perception alone as a means of valid knowledge. The validity of inferential knowledge was challenged on the ground that all inference requires a universal major premise ("All that possesses smoke possesses fire") whereas there is no means of arriving at a certainty about such a proposition. No amount of finite observations could possibly yield the required universal premise. The supposed "invariable connection" may be vitiated by some unknown "condition," and there is no means of knowing that such a vitiating factor does not exist. Since inference is not a means of valid knowledge, all such supersensible objects as "afterlife," "destiny," or "soul" do not exist. To say that such entities exist though there is no means of knowing them is regarded as absurd, for no unverifiable assertion of existence is meaningful.

 The authority of the scriptures also is denied. First, knowledge based on verbal testimony is inferential and therefore vitiated by all the defects of inference. The Carvakas regard the scriptures as characterized by the three faults: falsity, self-contradiction, and tautology. On the basis of such a theory of knowledge, the Carvakas defended a complete reductive materialism according to which the four elements of earth, water, fire, and air are the only original components of being and all other forms are products of their composition. Consciousness thus is viewed as a product of the material structure of the body and characterizes the body itself--rather than a soul--and perishes with the body. In their ethics, the Carvakas upheld a hedonistic theory according to which enjoyment of the maximum amount of sensual pleasure here in this life and avoidance of pain that is likely to accompany such enjoyment are the only two goals that men ought to pursue.