Nyāya Sūtras 2

Because there is efficacy of activity when an object is comprehended by a means of valid cognition, a means of valid cognition has purpose.

Without a means of valid cognition there is no comprehension of an object; without the comprehension of an object there is no efficacy of activity. For it is through a means of valid cognition that a person, having cognized an object, desires to obtain it or desires to avoid it. The exertion of one who is motivated by the desire to obtain or to avoid is called activity. Its 'efficacy', in turn, is its connection with the result: exerting oneself, desiring to obtain or desiring to avoid that object, one obtains that object or avoids it. And the object is pleasure and the cause of pleasure, and pain and the cause of pain.

This object of the means of valid cognition is innumerable, because the varieties of living beings are innumerable. And when the means of valid cognition has purpose, the cognizer, the object of valid cognition, and the valid cognition also have purpose. Why? Because if any one of them were absent, the object could not be established.

Among these, he who is prompted to activity by the desire to obtain or avoid is the cognizer; that by which he cognizes an object is the means of valid cognition; the object which is cognized is the object of valid cognition; that knowledge of the object which arises is the valid cognition; and the reality of things is fully contained within these four. What, then, is reality? It is the existence of the existent and the non-existence of the non-existent. The existent, being grasped as existent, is reality—accurate and non-erroneous.

And the non-existent, being grasped as non-existent, is reality—accurate and non-erroneous.

How is the latter apprehended by a means of valid cognition? Because when the existent is being apprehended, that [non-existent] is not apprehended, just as with a lamp. As when an object to be seen is grasped by an illuminating lamp, that which like it is not grasped does not exist: 'If it had existed, it would have been known just like this; because of the absence of cognition, it does not exist.' So, when an existent is grasped by a means of valid cognition, that which like it is not grasped,

does not exist: 'If it had existed, it would have been known just like this; because of the absence of cognition, it does not exist.' Thus, in this way, the means of valid cognition, revealing the existent, reveals even the non-existent.

And the existent will be taught as arranged in sixteen categories. Of these kinds of existents—

Attainment of the highest good results from the knowledge of reality of the means of valid cognition, the objects of valid cognition, doubt, purpose, example, established tenet, components of an inference, hypothetical reasoning, ascertainment, philosophical debate, disputation, cavil, pseudo-reasons, quibble, futile rejoinder, and points of defeat.

In this statement, the compound is analyzed according to the words as spoken. The dvandva compound is in the sense of 'and' (ca). The genitive case in 'the reality of the means of valid cognition, etc.' expresses a relation (śeṣa).

The two genitive cases in 'knowledge of reality' and 'attainment of the highest good' express the grammatical object (karman). These are just so many existing objects, for the non-erroneous knowledge of which instruction is given here.

This is to be known as the subject matter of the treatise stated in its entirety. Attainment of the highest good results indeed from the knowledge of reality of the object of valid cognition, beginning with the self.

And this is reiterated in the next aphorism: having correctly understood these four topics—that which is to be avoided, the cause of that, the ultimate cessation, and the means to that cessation which must be known—one attains the highest good.

On this point, is the separate mention of doubt and the rest useless, since doubt and the others are included within the means of valid cognition and the objects of valid cognition according to their nature, and are not distinct? That is true; however, these four disciplines, having distinct methodologies, are taught for the benefit of living beings, of which this critical inquiry, the science of reasoning, is the fourth.

Doubt and the other categories are its distinct methodological subjects. Without their separate mention, this would be merely a science of the soul, like the Upaniṣads. Therefore, it is established separately by means of categories such as doubt. In that regard, reasoning proceeds neither concerning an unapprehended object nor concerning an ascertained object. Concerning what, then? Concerning a doubted object. As has been stated: 'Ascertainment is the determination of an object by means of a thesis and counter-thesis after deliberation.' Deliberation is doubt; thesis and counter-thesis are the operation of reasoning; the determination of the object is ascertainment, which is knowledge of reality. And that doubt, being merely a deliberation upon an entity—a non-determinate cognition in the form 'What might this be?'—though included within the object of valid cognition, is stated separately for this purpose.

Now as for purpose: that motivated by which one acts is purpose. Desiring to obtain or desiring to avoid which object one undertakes action,

by that all living beings, all actions, and all disciplines are pervaded, and reasoning operates depending on that. What, then, is this reasoning? Reasoning is the examination of an object by means of the means of valid cognition.

Inference based on perception and testimony is 'critical scrutiny' (anvīkṣā). Scrutiny (anvīkṣā) is the re-examination of an object already examined by perception and testimony. Because it proceeds by means of that, it is 'critical inquiry' (ānvīkṣikī)—the science of reasoning, the treatise on reasoning. But an inference that contradicts perception and testimony is a pseudo-reasoning.

Among these, philosophical debate and disputation have a purpose. Cavil, however, is examined [as follows]: a caviller is one who engages through cavil. If, when questioned about his purpose, he accepts that 'this is his thesis, this is his established tenet', he abandons being a caviller. If he does not accept it, the consequence follows that he is neither an ordinary person nor a critical investigator. If, alternatively, he says that his purpose is making known the refutation of the opponent's thesis, even this is just the same: if he accepts who makes it known, who knows, by what means it is made known, and what is made known, then he abandons being a caviller. If he does not accept it, his statement that 'the purpose is making known the refutation of the opponent's thesis' becomes meaningless. And a collection of statements devoid of proof is cavil; if he accepts what is expressed by it, that becomes his thesis that must be proven. If he does not accept it, it becomes mere meaningless babble, and its nature as cavil ceases.
Now, an example is an object within the realm of perception, regarding which the understanding of ordinary persons and critical investigators is not contradicted.

And it is an object of valid cognition. Its separate mention is because inference and testimony depend upon it; if it exists, inference and testimony would exist, and if it does not exist, they would not exist. And the operation of reasoning depends on it. Through conflict with an example, the refutation of an opponent's thesis is to be stated; and by means of harmony with an example, one's own thesis is to be established. A denier of the next world, by accepting an example, abandons his denial; and by not accepting it, with what means of proof could he censure another? And through the defined example, it is possible to state: 'An example demonstrating similarity with the thing to be proved is an instance possessing its property,' [and] 'Through its opposite, it is the reverse.'

An established tenet is an object acknowledged as 'this is so'. And it is an object of valid cognition. Its separate mention is because, while different varieties of established tenets exist, philosophical debate, disputation, and cavil proceed, and not otherwise.

The components of an inference are five, beginning with the proposition, of that collection of words in which the establishment of the object to be proved is completed; with respect to the collection, they are called 'components'.

Among them is the confluence of the means of valid cognition: the proposition is testimony; the logical reason is inference;

the application is perception; the application is analogy;

the conclusion is the demonstration of the capacity of all [components] in the convergence on a single object. This is supreme reasoning. By this, philosophical debate, disputation, and cavil proceed, and not otherwise.

And on it rests the settlement of reality. And these components, being specific types of words, are included within the object of valid cognition; they are mentioned separately for this purpose.
Hypothetical reasoning is not included among the means of valid cognition, nor is it another means of valid cognition; aiding the means of valid cognition, it serves for the knowledge of reality. Its example is: 'Is this birth produced by a produced cause, or by an unproduced one, or is it uncaused?'

When an object is thus unknown, conjectural reasoning proceeds through the plausibility of causes: 'If it is produced by a produced cause, then this cessation of birth is plausible through the destruction of the cause. If, on the other hand, it is by an unproduced cause, then, because the destruction of the cause is impossible, the cessation of birth is implausible. If it is uncaused, then that which is produced without a cause will not cease again, so a cause of cessation is implausible; therefore there would be no cessation of birth.' When this is the object of hypothetical reasoning, the means of valid cognition operating [to prove] that birth is caused by karma are aided by hypothetical reasoning;

because of the distinction of the object of knowledge of reality, hypothetical reasoning serves for the knowledge of reality. Being of this nature, hypothetical reasoning, accompanied by the means of valid cognition, serves for the establishment and censure of an object in a philosophical debate; for this purpose it is mentioned separately, even though it is included within the object of valid cognition.

Ascertainment is the knowledge of reality, the fruit of the means of valid cognition; philosophical debate culminates in it; disputation and cavil are for the sake of protecting it. These two, hypothetical reasoning and ascertainment, conduct worldly affairs. This ascertainment, though included within the object of valid cognition, is mentioned separately for this purpose.

A philosophical debate, indeed, has multiple speakers, establishes distinct positions, and is a collection of statements culminating in the ascertainment of one or the other position.

It is mentioned separately for the sake of definition. Through what is defined, practice leads to the knowledge of reality. It has been said: 'Its modifications, disputation and cavil, are for the sake of protecting the firm conviction of reality.'

Pseudo-reasons are mentioned separately from points of defeat so that they will be raised in a philosophical debate;

the points of defeat, however, [are raised] in disputation and cavil.

The separate instruction of quibble, futile rejoinder, and points of defeat is for the sake of definition. [The purpose is] the avoidance in one's own speech of what has been defined, and the cross-examination of quibble, futile rejoinder, and points of defeat in an opponent's speech; and so that the resolution of a futile rejoinder employed by an opponent is easy to obtain, and its application by oneself is easy to make.

This critical inquiry, being divided by the categories beginning with the means of valid cognition:
A lamp to all branches of knowledge, a means to all actions,
A support for all duties, it is declared in the enumeration of sciences.

This knowledge of reality, for the sake of attaining the highest good, is to be understood according to each discipline. But here, in the science of the inner self, the knowledge of the self and the rest is the knowledge of reality. Attainment of the highest good is the attainment of final release. || 1