ShadPramanas (षड्प्रमाणाः)

Shad Pramanas (Samskrit: षड्प्रमाणाः) comprise the six pramanas accepted variously in the ancient astika darshanas, the Shad Darsanas (Nyaya, Vaiseshika, Samkhya, Yoga, Mimamsa (Purva Mimamsa) and Vedanta (also known as Uttara Mimamsa)).

परिचयः॥ Introduction

The theories of cognition (Pramana) formulated by the ancient thinkers, arose out of a need to understand valid cognition and Nyaya darshana offers the definition and lakshanas for Pramanas. Different Darshana shastras have accepted the need and function of Pramana but they have their unique principles about the nature and scope of the Pramanas. (Pages 39 to 42 of Reference ). Both Astika and Nastika schools of thought have their own explanations for the pramanas accepted by them, thus atleast ten pramanas have been put forth in various Darshanas. Of the ten pramanas, six of them are accepted in varying numbers by each school of Darshana shastras. Here we discuss briefly what the ten pramanas are and of them the shad pramanas which are accepted by the Astika darshanas.

प्रमाणसङ्ख्या ॥ Number of Pramanas

दशप्रमाणाः ॥ Dasa Pramanas

There are ten kinds of Pramanas, but in the matter of recognizing different pramanas, different schools of Indian Philosophy adopted divergent schemes. The number of pramanas accepted by them vary from one to eight. (Page 33 of Reference)

1. Charvakas accept pratyaksha pramana (perception) only as a single means of knowledge.
2. Vaiseshikas and Nastika Darshanas accept pratyaksha (perception) and anumana (inference).
3. Samkhya, Yoga, Dvaita, Visishtaadvaita schools of Uttara Mimamsa recognize 3 Pramanas - pratyaksha (perception), anumana (inference) and shabda or agama (verbal testimony) as the means of knowledge.
4. Naiyaayikas recognize 4 Pramanas - pratyaksha (perception), anumana (inference), shabda and Upamana (comparison) as the means of knowledge.
5. Prabhakara school of Purva Mimamsa accepts 5 Pramanas - pratyaksha (perception), anumana (inference) and shabda or agama (verbal testimony) and Upamana (comparison) and arthaapatti (presumption) as the means of knowledge.
6. Kumarilabhatta school of Purva Mimamsa and Advaita Vedanta of Uttara Mimamsa school both accept 6 pramanas - Pratyaksha (perception), Anumana (inference), Shabda or aagama (verbal testimony) and Upamana (comparison), Arthaapatti (presumption) and Abhaava or Anupalabdhi (negation or non-apprehension) as the means of knowledge.
7. Pauranikas admit the above 6 with the addition of Sambhava (probability or inclusion) and Aitihya (tradition or rumour).
8. Tantrikas recognize, along with the above 8, Chesta (indication) as the means of knowledge.
9. A few other thinkers accept, along with these 9, Pratibha (vivid imagination) as a source of knowledge.

In the Manimekhala, it is said that, according to Vedavyasa

षड्प्रमाणाः ॥ Shad Pramanas

Pramanas though are ten in number, six of them (Shad Pramanas) accepted by astika schools of darshanas are discussed here.

1. प्रत्यक्षम् ॥ Pratyaksha (perception)
2. अनुमानम् ॥ Anumana (inference)
3. शब्दः ॥ Shabda or aagama (verbal testimony)
4. उपमानम् ॥ Upamana (comparison)
5. अर्थापत्तिः ॥ Arthaapatti (presumption)
6. अभावः ॥ Abhaava (negation or non-apprehension)

Gautama in his Nyayasutras lays down that there are four kinds of Pramanas. Pratyaksha (Perception), Anumana (Inference), Upamana (Analogy) and Shabda (Words) are the Pramanas. (Page 36 of Reference )

प्रत्यक्षानुमानोपमानशब्दाः प्रमाणानि ।।३।। {प्रमाणौद्देशसूत्रम्} (Nyay. Sutr. 1.1.3)

प्रत्यक्षप्रमाणम् ॥ Pratyaksha Pramana

Knowledge which is produced by the contact of a sense-organ with an object is called pratyaksha pramana. Pratyaksha pramana is the primary and fundamental of all the sources of valid knowledge and it is universally recognized so by all schools of philosophy. According to Nyaya , perception is not the only source of our knowledge, but is the basis of the other sources or means of knowledge.

Pratyaksha (Perception) is a source of direct knowledge and leads one to apprehend the reality. All other means of knowledge are indirect sources of apprehending reality. Example: When the sense-organ, i.e. eye, comes in direct contact with a pot, there arises a perceptual knowledge of pot.

Etymology

Pratyaksha pramana (Samskrit : प्रत्यक्षप्रमाणम्) is made of two words Prati (प्रति) and Aksha (अक्ष), which literally means "In front of the eyes".

Gautama Nyaya Sutra 4

इन्द्रियार्थसन्निकर्षोत्पन्नं ज्ञानं अव्यपदेश्यं अव्यभिचारि व्यवसायात्मकं प्रत्यक्षम् ।।४।।{प्रत्यक्षलक्षणम्} (Nyay. Sutr. 1.1.4)

Meaning : Sense perception is that cognition which is

1. produced by the contact (सन्निकर्षाद्) of the sense organ (इन्द्रियम्) with the object (अर्थेः).
2. अव्यपदेश्यं not expressible by words
3. अव्यभिचारि not erroneous, non-deviatedness
4. व्यवसायात्मकं doubtless with crystal clear clarity (well-defined)

Vatsyayana Bhasyam

The bhashyam for Nyaya sutra (1.1.4)

इन्द्रियस्यार्थेन सन्निकर्षाद् उत्पद्यते यत् ज्ञानं, तत् प्रत्यक्षम् ॥ (Vats. Bhas. Nyay. Sutr. 1.1.4) (Page 59 of Reference )

The knowledge that arises by the means contact of sense organ with the object.

The constant connection of the means of valid cognition (Pramana) with the object (artha) is called nondeviatedness (अव्यभिचारित्वम्).

Annambhatta's Tarkasangraha, also ascertains the concept given by Nyaya sutras about Pratyaksha pramana. इन्द्रियार्थसन्निकर्षजन्यं ज्ञानं प्रत्यक्षम्।

अनुमानप्रमाणम् ॥ Anumana Pramana

The second instrument of valid knowledge is Anumana Pramana.

Gautama Nyaya Sutra 5

अथ तत्पूर्वकं त्रिविधं अनुमानं पूर्ववत् शेषवत् सामान्यतोदृष्टं च ।।५।। {अनुमानलक्षणम्} (Nyay. Sutr. 1.1.5)

Meaning : After perception comes Inference which is led up to by perception; it is of three kinds - Purvavat (पूर्ववत्), Sheshavat (शेषवत्), and Samanyatodrshtam (सामान्यतोदृष्टम्).

Vatsyayana Bhashyam

The meaning of the above sutra is explained by Vatsyayana bhashya as follows

तत्पूर्वकमित्यनेन लिङ्गलिङ्गिनोः संबन्धदर्शनं लिङ्गदर्शनं चाभिसंबध्यते । लिङ्गलिङ्गिनोः संबध्द्योर्दर्शनेन लिङ्गस्मृतिरभिसंबध्यते । स्मृत्या लिङ्गदर्शनेन चाऽप्रत्यक्षः अर्थः अनुमीयते । (Vats. Bhas. Nyay. Sutr. 1.1.5) (Page 65 of Reference )

Meaning : The expression तत्पूर्वकम् meaning 'led up to perception' refers to the darshana (perception obtained through the indriyas and manas) of the relation between the Linga (लिङ्ग । mark) and Lingi (लिङ्गि । object indicated by the mark) and also darshana of Linga itself. The darshana of the relation between linga (mark) and lingi (object) also implies Smrti (स्मृतिः । remembrance) of linga. Thus by means of Smrti and darshana of Linga (mark) the Apratyaksha (अप्रत्यक्षः । non-perceptible) object (अर्थः) is inferred (अनुमानम् । anumana). (Page 26 of Reference). Thus anumana depends totally on previous experiences through pratyaksha and this knowledge follows other kinds of knowledge. Example : where there is smoke there is fire.

Tarkasamgraha

According to Annambhatta's Tarkasamgraha Anumana is

अनुमितिकरणमनुमानम्॥१॥ परामर्शजन्यं ज्ञानमनुमितिः॥२॥ व्याप्तिविशिष्टपक्षधर्मताज्ञानं परामर्शः ।

Kinds of Anumana

Anumana is of three kinds with each of them having two definitions with elaborately described examples by Vatsyayana for the Nyaya Sutras given by Gautama.

Purvavat (पूर्ववत्)

पूर्ववदिति, यत्र कारणेन कार्य्यमनुमीयते। यथा मेधोन्नत्या भविष्यति वृष्टिरिति । (Vats. Bhas. Nyay. Sutr. 1.1.5) (Page 65 and 66 of Reference )

Purvavat Anumana is that in which the effect is inferred from the cause; e.g. when we see the clouds rising, we infer that there will be rain. The cause is 'purva' or prior to the effect ; hence that in which the Anumana is based on the cognition of the cause has been called Purvavat. (Page 26 of Reference )

अथवा पूर्ववदिति, यत्र यथा पूर्व्वं प्रत्यक्षभूतयोः अन्यतरदर्शनेन अन्यतरस्य अप्रत्यक्षस्य अनुमानम् । यथा धूमेनाग्निरिति । (Vats. Bhas. Nyay. Sutr. 1.1.5) (Page 65 and 66 of Reference )

Purvavat Anumana is that in which out of two things perceived on some former occasion, perception of one of the two things leads to inference of the other (which is not being perceived); e.g. when fire is inferred from smoke. (Page 26 of Reference )

Sheshavat (शेषवत्)

शेषवत् यत्र कार्य्येण कारणमनुमीयते । पूर्व्वोदकविपरीतमुदकं, नद्याः पूर्णत्वमं, शीध्रत्वञ्च दृष्ट्वा स्रोतसोऽनुमीयते भूता वृष्टिरिति । (Vats. Bhas. Nyay. Sutr. 1.1.5) (Page 65 and 66 of Reference )

Sheshavat Anumana is that in which the cause is inferred from the effect; e.g. when we see that the water of the river is not like what it used to be, and that the stream is fuller and the current swifter, we infer that there has been rain in the catchment areas. (Page 26 of Reference )

शेषवत् नाम परिशेषः, स च प्रसक्तप्रतिषेधेऽन्यत्र अप्रसाङ्गात् शिष्यमाणे सम्प्रत्ययः । यथा सदनित्यमित्येवमादिना द्रव्यगुणकर्मणामविशेषेण सामान्यविशेषसमवायेभ्यो विभक्तस्य शब्दस्य तस्मिन् द्रव्यकर्मगुणसंशये न द्रव्यमेकद्रव्यत्वात्, न कर्म शब्दान्तरहेतुत्वात्, यस्तु शिष्यते, सोऽयमिति शब्दस्य गुणत्वप्रतिपत्तिः । (Page 65 and 66 of Reference )

The word sheshavat means remainder; with regard to an object there are certain possibilities - and some of these possibilities are eliminated; and there being no other possibilities - when the remaining possibility is cognised in relation to the said object, this cognition is Sheshavat. e.g. with regard to Sound, we find that it is an real entity (सत्) and is transient (अनित्यमम्) etc; and as these properties (being an entity and being transient etc) are found to be common to Substances (द्रव्यम्), Qualities (गुणः) and Actions (कर्म) only, their presence in Sound distinguishes it from the remaining categories of the Commoness (सामान्यम्), Specialness (विशेष्यम्) and Samavaya (समवाय । Pervasiveness) (all of which are three entities, but eternal). Now there arises a doubt as to whether Sound is a Substance, a Quality or an Action. This doubt is reasoned (by the process of elimination) in the following manner :

• Sound cannot be a Substance (द्रव्यम्), because it pervades in a single substance (Akasha). No other dravya is pervasive only in one dravya. All Substances are either not inherent in any dravya (e.g. Atman) or inherent in more than one dravya (e.g. a jar).
• Sound is not an Action (कर्म), because it is the originator of another sound, thus it gives rise to something that is of its own kind which is never the case with any action.
• Sound is thus a Quality (गुणः) arrived at by the process of elimination of the other two. (Page 27 of Reference )

Samanyatodrshtam (सामान्यतोदृष्टम्)

सामान्यतो दृष्टं व्रज्यापूर्वकम् अन्यत्र दृष्टस्य अन्यत्र दर्शनमिति तथा चाऽऽदित्यस्य । तस्मात् अस्ति अप्रत्यक्षा अपि आप्यादित्यस्य व्रज्येति। (Page 65 and 66 of Reference )

Samanyatodrsta Anumana (is that in which the inference is based on a general observation) e.g. we have observed in all cases that we see a thing in a place different from where we saw it before only when it has moved; from such general observation we infer that the sun must be moving, even though we cannot perceive it. (Page 26 of Reference )

सामान्यतो दृष्टं नाम, यत्राप्रत्यक्षे लिङ्गलिङ्गिनोः सम्बन्धे केनचिदर्थेन लिङ्गस्य सामान्यादप्रत्यक्षो लिङ्गी गम्यते । यथेच्छादिभिरात्मा । इच्छादयो गुणाः । गुणाश्च द्रव्यसंस्थानाः । तद्यदेषां स्थानं स आत्मेति । (Page 65 and 66 of Reference )

Samanyatodrsta Anumana is that in which, the relation between the Linga and Lingi being Apratyaksha (imperceptible), the imperceptible Lingi is inferred from the similarity of the Linga (mark) to something else. e.g. When the Atma is inferred from Desire etc. Desire etc are a Qualities and Qualities always pervade in substances. Similarity of Desire to other qualities which pervade in substances leads to the Anumana that, that Substance in which Desire pervades is the Atma. (Page 27 of Reference )

Upamana Pramana

The third instrument of knowledge is called Upamana Pramana or Analogy. The knowledge of similarity is generated by Upamana. This knowledge arises by the use of comparison of two things and the presence of some common factors in a thing.

Etymology

It is derived from the words Upa (उप) used in the meaning सादृस्य । saadrisya or similarity and मान । maana in the sense of measuring or cognition.

However, the word Upamana has been translated variously as comparison, analogy, identification, knowledge by similarity and knowledge by assimilation.

Gautama Nyaya Sutra 6

Gautama defines Upamana as below

प्रसिद्धसाधर्म्यात्साध्यसाधनं उपमानम् ।। ६ ।। {उपमानलक्षणम्}

Upamana (Analogy ) is that which accomplishes its purpose through similarity to a known object.

Vatsyayana Bhasyam

The bhashyam on Nyaya sutra 6 is as follows

प्रज्ञातेन सामान्यात्प्रज्ञापनीयस्य प्रज्ञापनमुपमानमिति । यथा गौरेवं गवय इति । यदा खल्वयं गवा समानधर्मं प्रतिपद्यते तदा प्रत्यक्षतस्तमर्थं प्रतिपद्यत इति । समाख्यासम्बन्धप्रतिपत्तिः रूपमानार्थ इत्याह । यथा गौरेवं गवय इत्युपमाने प्रयुक्ते गवा समानधर्ममर्थमिन्द्रियार्थसन्निकर्षादुपलभमानो अस्य गवयशब्दः संज्ञेति संज्ञासंज्ञिसम्बन्धं प्रतिपद्यतइति । यथा मुद्गस्तथा मुद्गपर्णि यथा माषस्तथा माषपणि इत्युपमाने प्रयुक्ते उपमानात् संज्ञासंज्ञिसम्बन्धं प्रतिपद्यमानस्तामोषधीं भैषज्यायाहरति । एवमन्यो अप्युपमानस्य लोके विषयो बुभुत्सितव्य इति । (Page 69 and 70 of Reference )

Meaning : Analogy is that which makes known what is to be made known, through similarity to an object that is already well known ; e.g. the assertion 'as the cow so do the gavaya' i.e., animal called gavaya is like the cow.

A person, who has perceived a cow in a town goes to a forest, and perceives a wild cow. He has an apprehension "this animal is similar to a cow" owing to the meeting of his eyes with the animal.. This knowledge of similarity of a cow with a wild cow is acquired by comparison.

Shabda Pramana

The fourth instrument of knowledge is called as Shabda or Word. This knowledge depends on reliable authority and also on yogyata aakaksha, and aasatti of a sentence. Different sounds such as those arising from musical instruments and bamboos also contribute to the realization of this knowledge. Shabda literally means verbal knowledge, that evidence about objects realized by the power of words and sentences is called Shabhda pramana.

Etymology

According to Panini's dhatupata, the word शब्दः is derived from the dhatu श॑ब्दँ॑ used in the meaning of भाषणे शब्दक्रियायाम् उपसर्गादाविष्कारे च (speaking, in sound utterances, and revealing the meanings of upasargas)

Gautama Nyaya Sutras 7 and 8

आप्तोपदेशः शब्दः।।७।।{शब्दलक्षणम्}

सः द्विविधः दृष्टादृष्टार्थत्वात्।।८।।{शब्दभेदः}

The communication made by a reliable person is Shabda (word). The said word is of two kinds - Drsthartha, where the thing spoken of is perceived (drstha) here and the Adrsthartha, where the thing spoken of is not perceived (adrshta). (Page 49 and 50 of Reference )

Vatsyayana Bhashyam

अाप्तः खलु साक्षात्कृतधर्मा यथादृष्टस्यार्थस्य चिख्यापयिषया प्रयुक्त उपदेष्टा । साक्षात्करणमर्थस्य आप्तिः, तया प्रवर्त्तत इत्याप्तः । ऋष्यार्य्यम्लेच्छानां समानं लक्षणम् । (Page 70 of Reference )

Meaning : That person is called 'Apta' , 'reliable' who possesses the direct (साक्षात्) and right knowledge of things. He is moved by a desire to express the thing exactly according to his knowledge and is fully capable of speaking it. Apta can be rshis, aryas and mlecchas. (Page 50 of Reference )

यस्यामुत्र प्रतीयते, सोऽदृष्टार्थः । एवमृषि लौकिकवाक्यानां विभाग इति । (Page 71 of Reference )

Where the thing spoken of is only believed to exist elsewhere is Adrstha and cannot be perceived here. This way the words and sentences given by rshis and ordinary men are differentiated. (Page 50 and 51 of Reference ).

Yoga darshana

Shabda pramana is also called as Agama pramana, sastra pramana according to the Yoga darshana.

प्रत्यक्षानुमानागमाः प्रमाणानि ॥ १.७ ॥

Meaning : Pratyaksha Anumana and Agama are the three pramanas.

"Agama," literally means "that which has come", contextually it means that evidence which is realized by the process of understanding scriptures from rshis who constitute reliable authority.  

In general according to our tradition Agama pramanas are divided in two parts -

• Apaurusheya : Vedas.
• Paurusheya : Puranas, dharma sastras, and smritis along with other words of rishis and elders. Basically paurusheya pramanas ultimately do not and should not contradict the Vedas.

Shabda pramana is designated in various ways by the different schools of Indian Darshanas. Thus, it is "shabda", according to Naiyayikas and Mimamsakas, "Shastra" according to Vedantins, "Aptavachana" according to Samkhya and "Aagama" to Yoga darshana.

तया च सर्वेषां व्यवहाराः प्रवर्तन्त इति । एवमेभिः प्रमाणैर्देवमनुष्यतिरश्च व्यवहाराः प्रकल्पन्ते नातोऽन्यथेति ।

Thus concludes the bhasyam of the 4 pramanas given by Nyaya sutras.

Arthaapatti Pramana

Arthapatti is the presumption of something for the explanation of a known fact. The word arthaapatti gies under various translations as presumption, postulation, supposition, implication, and assumption. When a given or perceived fact cannot be explained without some other fact we have to presuppose or postulate the existence of this other fact even though we do not perceive it. Example : when a particular person named Chaitra, known to be alive, is not found in his house, it is assumed that he must be somewhere outside. What is presumed is said to be a distinct source of knowledge.

Anupalabdhi Pramana

According to Kumarila Bhatta Mimamsa and Advaita Vedanta Anupalabdhi is an independent pramana.

The concept of Abhava (negative existence) has been discussed in two forms, namely, actual presence or absence of a thing (reality) and knowledge of the same. Reality of existence is expressed by words such as asat, alika, nirupakhya etc, while the way of knowing it is expressed as Anupalabdhi. Simply put, negation is that there is some reality known as Abhava and the means to ascertain it is known as Anupalabdhi. Even though Kanada explains the concept of Abhava in his Vaiseshika sutras, the means of knowing it as as a pramana (Anupalabdhi) has been put forth by the Bhattas and their close followers the Vedantins.

Knowledge by which we immediately cognize the non-existence of an object, e.g. absence of rainfall indicates that the connection of cloud and the wind has not happened.

Pramanas in Astika Darshanas

It is generally admitted by all the schools of philosophy that pramaa is the true knowledge and pramaana is the source of such knowledge. However, difference of opinions exist as to the the nature of the truth which each of them claims for its pramaana. The sutras and commentaries which explain the various Pramanas accepted by each of the astika Shad Darshanas are henceforth addressed in this context.

Samkhya

Samkhya and Yoga concept of pramana is different and original from all the other mentioned views.

Yoga

Yoga Darshana accepts 3 Pramanas as given by Patanjali with the explanation given by Vyasa.

प्रत्यक्षानुमानागमाः प्रमाणानि ॥७॥

Pratyaksha (Perception), Anumana (Inference) and Agama (Verbal testimony) are Pramanas.

Vyasa Bhasya

इन्द्रियप्रणालिकया चित्तस्य बाह्यवस्तूपरागात्तद्विषया सामान्यविशेषात्मनोऽर्थस्य विशेषावधारणप्रधाना वृत्तिः प्रत्यक्षं प्रमाणम् । फलमविशिष्टः पौरुषेयश्चित्तवृत्तिबोधः ।

अनुमेयस्य तुल्यजातीयेष्वनुवृत्तो भिन्नजातीयेभ्यो व्यावृत्तः सम्बन्धो यस्तद्विषया सामान्यावधारणप्रधाना वृत्तिरनुमानम् । यथा देशान्तरप्राप्तेर्गतिमच्चन्द्रतारकं चैत्रवत्, विन्ध्यश्चाप्राप्तिरगतिः ।

आप्तेन दृष्टोऽनुमितः वा अर्थः परत्र स्वबोधसङ्क्रान्तये शब्देनोपदिश्यते । शब्दात्तदर्थविषया वृत्तिः श्रोतुरागमः । यस्याश्रद्धेयार्थो वक्ता न दृष्टानुमितार्थः स आगमः प्लवते ।

Summarizing the Vyasa Bhashya given above an object naturally has generic (सामान्या) and specific (विशेषः) attributes. The Pratyaksha pramama considers the specific aspect of the object. Chitta when affected by the external object through the path of sense-organs gives rise to a function with the specific attribute of that object. Such a function is called Pratyaksha pramana. The effect of Pratyaksha pramana ultimately is that the Purusha cognises the function of Chitta (चित्तवृत्तिबोधः).

Further Anumana or Inference is explained. There is a certain relationship which is common (अनुवृत्तिः) to all homogenous objects (तुल्यजातीयेषु) and dissociated (व्यावृत्तः) from the heterogenous ones (भिन्नजातीयेषु). Anumana is that function having the above said relationship for its object concerned chiefly with the ascertainment (अवधारणप्रधाना) of its generic attribute. For e.g. a person, say Chaitra, changes his position only through movement. Similarly when we see planets changing their positions we infer that there is movement, just like in Chaitra, which cannot be perceived. On the other hand, Vidhya mountain does not change its position so we infer that there is no movement.

A certain object, having been either perceived or inferred by an authoritative person, is verbally expressed for the sake of transferring that cognition to another person. Vrtti (function of the object) generated by verbal transfer of cognition is Agama for the listener. That Agama given by an untrustworthy person, who has neither seen nor inferred an object fails.

Yoga holds that pramana is the function of chitta. Samkhya considers knowledge as belonging to buddhi only, which though essentially is insentient, acts like a sentient entity when the sentience of Purusha is reflected upon it. Both these systems offer an original definition of pramana as the function of the buddhi or chitta.

Nyaya

According to Nyaya darshana, pramana is the unique operative cause (kaarana) of pramaa or right knowledge. It is the complex of specific conditions or causes (karana), other than the subject and the object, which invariably produces valid knowledge.

प्रत्यक्षानुमानोपमानशब्दाः प्रमाणानि ।। ३ ।। {प्रमाणौद्देशसूत्रम्}

Vaiseshika

Kanda who occupies the first place in traceable history of epistemological tradition states that the general definition of pramana should be based on the principle that the cause of cognition should be free from defects (अदुष्टं विद्या । वैशेषिक-९,२.१२ । adustam vidya (Vais. Sutr. 9.2.12)

Mimaamsa

Mimamsa sutras firmly affirm that Vedas are the source of Dharma. They con

Pratyaksha Pramana

सत्संप्रयोगे पुरुषस्येन्द्रियाणां बुद्धिजन्म तत्प्रत्यक्षम्...१,१.४ (Mima. Sutr. 1.1.4)

A contact between an object and indriyas generates Knowledge for Purusha and it is called Pratyaksha. Shabda Pramana - Vedas

औत्पत्तिकस् तु शब्दस्यार्थेन संबन्धस् तस्य ज्ञानम् उपदेशोऽव्यतिरेकश् चार्थेऽनुपलब्धे तत्प्रमाणं बादरायणस्यानपेक्षत्वात् -१.१.५

On the other hand, the relation of the word with its meaning is eternal. Consequently Upadesha (injunctions or vedopadesa) is the means of knowing dharma and it is undeviated in regard to objects not perceived by other means of knowledge. It is authoritative specially as it is independent according to Badarayana. Page 23 of Link Shabda Pramana - Smrtis

अपि वा कर्तृसामान्यात् प्रमाणम् अनुमानं स्यात् -१,३.२

But on account of Karta (teacher and preacher of Veda and Smrtis) being the same, inference would be that Smrti is also pramana just like the Vedas. Page 72 of Link

Bhatta Mimamsa, considers prama or true knowledge as the primary and original knowledge (anaadigata). Hence pramaana is that which gives us new knowledge, i.e. a true cognition of objects of which we have no experience in the past. The method of knowledge must be concerned in knowing what has not been previously known. It has no new contents but refers only to the already acquired contents of knowledge. (yathaarthamagrhitagraahitknaanam pranam iti SD pg 45) Thus pramana is that which gives us new knowledge, i.e. a true knowledge of the past (anadhigataarthaabhutarthanischayatmakam pramanam SD pg 123)

See Reference for sloka and translation.

Prabhakara Mimamsikas, define prama or valid knowledge as immediate experience (Anubhuti). It is different from smriti or memory which is the impression of past experiences. (pramanamanubhutihi sa smrteranyaa PP, p.42). Hence according to them the truth of knowledge, praamaanya is guaranteed by its having the characteristic of immediacy.

Advaitha Vedanta

Advaita vedanta also defines pramana as the operative cause (kaarana) of prama or ture knowledge. It defines prama in two ways. First, prama means knowledge that has both the characteristics of novelty and uncontradictoriness. This means that true knowledge is uncontradicted and original, i.e. it gives us new information. Secondly, prama simply means uncontradicted knowledge of objects, excluding or including memory.