Nyāya Sūtras 41

Next, hypothetical reasoning is to be defined; therefore, this is said:

Nyāyasūtra 1.1.40: With regard to an object whose reality is unknown, hypothetical reasoning is deliberation from the presence of grounds for the sake of knowledge of reality.

With regard to an object whose reality is not known, first there arises the desire to know: 'May I know this object.' Then, with respect to the thing desired to be known, one deliberates distinctively upon two contradictory properties:

Is it like this, or is it not like this? Between the two properties under consideration, he approves one on the basis of reasons being plausible: thinking that a cause, a means of valid cognition, a logical reason is possible for this [side], it would be this way, not the other, through the plausibility of reasons. Here is an illustration: there is the desire to know: 'May I know in reality this cognizer who knows the object to be known.' The consideration is: 'Does he have the property of being produced, or the property of being unproduced?' When the object whose reality is unknown is being considered, he approves that property for which a reason for acceptance is plausible: 'If this [cognizer] has the property of being unproduced, then the cognizer experiences the result of his own performed action; [and] of pain, birth, activity, defect, and false knowledge, each subsequent one is the cause of each prior one, and upon the cessation of each subsequent one, due to the cessation of that immediately prior to it, there is liberation—thus transmigratory existence and liberation would be possible.'

If, on the other hand, the cognizer had the property of being produced, [transmigration and liberation] would not be possible. For a produced cognizer would be connected with body, sense organs, intellect, and feelings, so this [result] would not be the fruit of his own performed action; and having come into existence, he ceases to exist, so for him, non-existent or destroyed, there is no experience of the fruit of his own performed action. Thus, connection of one [and the same self] with many bodies and absolute separation from the body would not occur. Where he sees that a reason is not plausible, he does not approve that [side]. Reasoning of such a character is called hypothetical reasoning. But how is this for the sake of knowledge of reality, and not knowledge of reality itself? Because of the absence of determination. He approves one or the other property through the plausibility of reasons, but he does not determine, does not resolve, does not ascertain: 'This is precisely so.' How is it for the sake of knowledge of reality? Because it is produced from the capacity of an unobstructed means of valid cognition that follows, cultivated by the favor characterised by approval of the object of the knowledge of reality—in this way it is for the sake of knowledge of reality. This hypothetical reasoning, synthesising the means of valid cognition, because it approves the means of valid cognition, accompanied by means of valid cognition, is designated in philosophical debate; thus it approves [the property of] an object whose reality is unknown.

The being of that thing as it actually is, is reality; it is the non-contrary state of affairs, truth. ||40