In this article, Suhotra Swami discusses various approaches to acquiring knowledge.� He examines this phenomena in terms of the three pramanas (pratyaksa, anumana and sabda), which are the recognised sources of knowledge in the Vaisnava tradition. Suhotra Swami explains that in Vaisnava epistemology sabda (hearing from an authoritative source) is accorded the greatest regard.� He examines the methods of direct perception and logical argument and offers an interesting analysis of their limitations in comparison to sabda as a source of infallible and transcendental knowledge.
'How can I be certain that what you are telling me is true?' Every thinking person asks, and is asked, this question. Vedic philosophy arrives at certitude through pramana, which refers to sources of knowledge that are held to be valid. In the Brahma-Madhva-Gaudiya Sampradaya, the school of Vedic knowledge that ISKCON represents, there are three pramanas: pratyaksa (direct perception), anumana (logical argument) and sabda (authoritative testimony). Of these, sabda is imperative, while pratyaksa and anumana are supportive. Therefore, when a devotee of Krsna is asked about the certainty of his beliefs he usually answers by quoting authority: guru (the spiritual master), sastra (the Vedic scriptures) and sadhu (other devotees respected for their realisation of the teachings of guru and sastra).
In Western schools of thought, citing authority to certify what we say doesn't seem to count for much any more. There is a Latin phrase for this kind of proof, ipse dixit ('he himself has said it'), which is the answer that disciples of an ancient Greek sage used to give whenever an opponent called the sage's doctrine into question. The problem modern thinkers have with ipse dixit is that its evidence lies only in words. And words alone don't prove anything.
Lucy in the land of Narnia C. S. Lewis, in The Chronicles of Narnia, illustrates the modern difficulty with ipse dixit proof. In the story, an odd thing happens to Lucy, the youngest of four children visiting the large, eccentric home of an elderly professor: she passes through the back of a clothes closet into another land called Narnia. When Lucy returns and relates her experience to her brothers and sister, they conclude that her senses had to have been mysteriously deluded. The children finally bring the matter before an authority, the professor himself. His decision is that because Lucy is not known to be a liar, nor mad, she must be telling the truth. Lucy's brother Peter still cannot believe it. He argues that the other children found no strange land through the back of the closet.
'What's that got to do with it?' the professor asks.'Well, Sir, if things are real, they are there all the time.'
'But do you really mean, Sir,' demands Peter, 'that there could be other worlds - all over the place, just around the corner - like that?''Nothing is more probable,' the professor replies. 
In a modernist analysis of the story, Peter probably would be called a reasonable young man who was right to doubt his hyper-imaginative sister Lucy. As for the professor, bless him, he must be well into his second childhood. Modernists similarly compare the Vedic description of worlds other than ours to the fantasies of children and dotty senior citizens. Just because some devotee saw something he thought was the spiritual world and his guru, by referring to some old book, confirmed his disciple saw the spiritual world, doesn't make the existence of the spiritual world certain. Another Latin phrase sums up the modernist outlook: de omnibus dubitandum ('doubt is everything'). This was coined by Ren� Descartes (1596-1650), often called the father of modern philosophy.
As every student of European philosophy knows, Descartes doubted what he perceived with his senses; he also questioned the ipse dixit authority of his education in the Greek classics. From out of these doubts arose a certitude about his own being, which he expressed in his famous maxim, 'I think, therefore I am'. Oxford philosopher A. J. Ayer explains, 'The sense in which I cannot doubt the statement that I think is just that my doubting entails its truth: and in the same sense I cannot doubt that I exist.' (Ayer, 1956:45)
The modern method of thought
Doubt itself, then, formed Descartes' immediate, indubitable data. From there he doubted his way to an understanding of the external world, questioning at every step both his senses and the teachings of previous authorities. His method looks natural and normal to people today, but for his time it was a radical break from the Medieval intellectual tradition. Descartes' method of systematic doubt marks the starting point of scientific rationalism.
What would Descartes do with Lucy's story of Narnia? As he himself wrote, 'In our search for the direct road to truth, we should busy ourselves with no object about which we cannot attain a certitude equal to that of the demonstrations of arithmetic and geometry.' (Descartes, 1701) In other words, the reality of a thing is to be certified by a system of logical proof (anumana), like geometry. It is not enough just for Lucy to see Narnia (pratyaksa), or even get authoritative confirmation that she saw it (sabda). If anumana certifies it, then Narnia exists even if Peter can't see it or didn't learn about it in school. If anumana doesn't certify it, Narnia doesn't exist, no matter what Lucy saw or the professor says.
As physicist Paul Davies points out, Descartes' method of analytic geometry is a historical antecedent to today's quantum physics, which also promotes anumana over sabda and pratyaksa. (Davies, 1992:166) Like Descartes, the modern scientist relies upon a system of mathematical logic to decide what is real and what is not. And, like Descartes, he asserts that mathematical proof overrides even direct perception. The old adage, 'seeing is believing', is out the window. We cannot see quarks, black holes or space-time worms, but the calculations tell us they exist - therefore they are certain.
The quantum Narnia As many of us may know from popular science magazines and pocketbooks, quantum theory mathematically proposes the existence of 'alternative worlds' that influence our own. (Davies, 1988:67) For example, suppose Lucy drops her claim of having directly seen Narnia and instead tells her siblings, 'Physicists say that the structure of everything rests upon mathematical laws. They also say there are unlimited other universes in mathematical dimensions. Given the infinite possibilities involved, I am completely certain that in one of these other parallel universes is a place called Narnia.'
The professor concurs that she is right. Still Peter protests, 'Do you really mean, Sir, that there could be other worlds - all over the place, just around the corner - like that?'
'Nothing is more probable,' the professor replies.
'Peter,' Lucy chimes in, 'you should pay attention to the professor now. This is no fairy tale. It's science. You were right to be dubious about the original form of my Narnia tale. But throw in a little physics and hey presto. It's rather tame, actually. We've heard so much about the quirky quantum world that by the mid-1990's, Narnia is just cold pudding.'
Many educated people today would tend to agree with Lucy. But Peter remains dubious that the quantamised tale of Narnia is any more credible. These are his reasons: 'Even if I say I believe you now, I still don't get to see Narnia for myself. Quantum physics says that the alternative worlds are completely disconnected from each other. Communication between them is impossible. An individual cannot leave one world and visit another, nor can we even glimpse what life is like in all those other worlds. (Davies, 1988:137) Not only can't you show me Narnia, you can't even give me a solid reason for believing that Narnia exists, because as a kid I'll never be able to work out the mathematics for myself. Admit it Sir, you're asking me to swallow the same old ipse dixit proof as before!'
His voice kind and fatherly, the professor patiently says, 'Peter, settle down. In the original tale of Narnia, Lucy's only evidence was her direct perception. We can't trust that because, after all, she's only human. But logic is more developed than perception. Therefore the quantum explanation is superior. Since your perception is also untrustworthy, you're not able to use it to question logic and mathematics. Even if you can't understand the quantum method of logic, it has an authority of its own, different from ipse dixit proof.'
'Are you telling me the quantum Narnia has the certain authority of truth?'
'Peter, I said nothing could be more probable. I didn't guarantee that it is true. The point is that scientific logic has its own authority that is worth your while to listen to and follow, young man.'
'No doubt, Sir, scientific logic is more developed than the simple words of a little girl, but it seems to me that you're the one missing the point. If we simply believe scientific theories without verifying whether they are true, we grant the scientists testimonial authority over our lives, not just theoretical authority. Theoretical authority means I'm giving you a hearing just for argument's sake; I may accept what you say or not. But testimonial authority supposes you to be speaking real facts that I, as a schoolboy, ought to take seriously if I want knowledge. You admit you cannot guarantee that what you are saying about Narnia is true, there is no evidence by direct perception that Narnia is real, yet still you expect me to grant you testimonial authority. But how can I be certain that what you are telling me is true?'
Self-evident authority To summarise, Peter and the professor disagree whether logic has authority. The professor's position is that if a statement is backed up by scientific logic (which he admits is not necessarily true), it has authority and should be accepted as testimony. Peter argues that logic in itself does not have the certain authority of truth. He accuses the professor, and modern science, of requiring schoolchildren like himself to believe in theories about unseen things like Narnia as if they were true. This is just the sort of ipse dixit authority that Descartes rejected.
Peter's objection to the authority of logic is well worth marking. A notorious problem of modern systems of reason is that their claims to authority are beyond reason. For example, what is the reason for the professor's argument that logic is the better method to certitude? The professor admits that logic does not guarantee truth. He speaks in terms of probability instead. But if the truth cannot really be guaranteed through logic, then how can we establish whether something is even true? Therefore, the professor's argument for logical certification of knowledge is not at all reasonable.  If his reason for the authority of logic is without reason, he is not really making an argument. Rather, he is putting forward an axiom: 'Logic has authority because I say so.'
Why should we accept his axiom because he says so? This is the essence of Peter's challenge. In the same way, the reason for granting authority to sense perception (pratyaksa) cannot be defended from sense perception itself. Our senses are limited. They cannot prove that there is no reality beyond their limits of perception. Thus there is no firm reason for giving final authority to sense perception in questions of certitude.
Like Peter, Vedic pramana distinguishes between logic and testimonial authority. The word sabda means 'sound', but the sabda that is cited as authoritative Vedic testimony is sabda-brahmana, spiritual sound. It is in a category by itself, distinct from anumana (logic) and pratyaksa (direct perception). Spiritual sound, as opposed to ordinary sound, is svatah-pramana. That means its authority is self-evident; it does not derive it from another pramana. Srimad-Bhagavatam (6.3.19) points out the essential difference between speech that carries self-evident authority, and speech that does not.
dharmam tu saksad bhagavat-pranitam
na vai vidur rsayo napi devah
na siddha-mukhya asura manusyah
kuto nu vidyadhara-caranadayah
'Authoritative laws of religion (dharma) are those directly spoken by the Supreme Personality of Godhead. Even the great sages in the higher planets cannot ascertain the real religious principles, nor can the demigods or the leaders of Siddhaloka, to say nothing of the asuras, ordinary human beings, Vidyadharas and Caranas.'
What Krsna says has the full authority of truth. Krsna Himself is the Supreme Truth, the Param Brahman. Bhagavad-gita (10.12-3) states that great sages like Asita, Devala and Vyasa 'confirm' this truth. That does not mean that the truth Krsna speaks depends upon the confirmation of others. The sages confirm they know the truth by repeating what Krsna says. Thus they are also accepted in the Vedas as authorities whose words are always true, because their authority derives from Krsna. Apart from this, sages, demigods, angels, human beings and demons have no self-evident authority.
Similarly, sense perception and logic have no self-evident authority; they depend upon sabda. For instance, I perceive that people die. Logical doubt impels me to ask whether every human being, including myself, will also die. But my senses and mind cannot answer that with certitude. I must turn to authoritative testimony. After learning from this that I and everybody else will indeed die, logical doubt then forces me to ask, 'what is the use of this life?' As before, the senses and mind cannot give me a certain answer. Only sabda has that authority.
Anumana can help us form a logical basis for a belief in worlds other than our own, as quantum physics does. But logic cannot even bring us to the realisation, with complete certainty, of other worlds in a different material dimension, let alone the certain realisation of transcendental worlds in the spiritual dimension (Vaikuntha). The spiritual dimension is self-evident only via the medium of sabda, pure Vedic sound as transmitted by Krsna and His authorised representatives. On the other hand, sound spoken by someone who has no self-evident authority, who does not refer to Krsna and who derives authority from pratyaksa and anumana, is not sabda. If we parrot such empty sound as ipse dixit evidence, it certifies nothing.
Problems of self-referential logic
Are we, who adhere to Vedic philosophy, being too credulous when we quote sabda as certain proof? Is there any rationality whatsoever in the concept of self-evident authority? Well, Descartes is still famous as a great rationalist. The central theme of his philosophy, the so-called Cartesian principle, is that anumana bears self-evident authority. He believed that the mind, by referring to itself alone, can arrive at the fundamental certainties of existence: I exist, God exists, and geometric logic is intrinsically superior to all other types of knowledge. Nowadays it is fashionable for philosophers to reject Descartes' arguments for the existence of the soul and God, as simply a result of his Christian upbringing. Still, the basic theme of the Cartesian principle, that the mind must decide for itself what is true and what is not, is an almost obligatory dogma in the West. In Western philosophical language, truth that the mind finds within itself alone is called a priori, self-evident.  If the truth about everything is knowable only by logical doubt, then truly, de omnibus dubitandum, "doubt is everything."
Descartes tried to establish his self-referential principle by equating thought ('I think') with the self ('therefore I am'). To the Christian that he was, 'I am' meant 'I am an eternal soul, different by my thought from matter'. His basis of certitude was formed by this sense of non-physical identity. From that basis, he devised his 'indubitable' Cartesianism. But all his maxim really says with any certitude is, 'I am thinking now, therefore I exist now'. The self does not always engage in thought. Sometimes it is completely unconscious, as during dreamless sleep. If thought or logical doubt is the self's nature, and thought is not always, then it does not follow that the self is always. 'I think, therefore I am' is no more or less valid a statement than 'I sleep, therefore I am not'.' Anumana, then, does not self-referentially establish a certain ground of eternal existence.
A second problem is that self-referential logic leads to paradox. Everyone who regularly uses a computer has experienced a 'hang', when the computer gets stuck in a function and cannot execute further commands. The only remedy is for the operator to reset the system. A 'hang' happens when the computer slips into a logical loop that keeps referring back to itself. In the same way, our minds slip into a logical loop as we consider Descartes' own central theme: doubt is everything. If the statement is true, it is false, because by asserting that doubt is everything, it leaves no doubt about what everything is. But if it is false, then it is true, because the falsity of the statement provokes doubt in everything once more. Yet again, if it is true, it is false; but still, if it is false, it is true ... on and on without end. There is no way out of the loop because the logic of the statement has only itself to refer to. This strongly suggests that for logic to be meaningful, it must be directed by truth beyond itself, just as a 'hang' must be reset by an operator external to the computer itself. Truth, then, is something beyond anumana.
A third problem is that Descartes himself could not put into practice the tenet of self-referential anumana. He did experiments to test his theories, resorting to observation (pratyaksa) to support his anumana.
I am not the mind
Descartes' intentions were pious. With his maxim, 'I think, therefore I am', he offered everyone a simple method of self-realisation which he believed certified our identity as soul. He hoped his method of logical analysis would put religion on a rational footing. Unfortunately, his method does not really lead to self-realisation, because it confuses the soul with the mind.
Vedic sabda reveals truths the mind is unable to discern by referring to itself. One such truth is that the mind is a subtle material covering of consciousness, something like a cloud of smoke hanging around a flame that is not burning cleanly. The flame is comparable to the soul, for the flame spreads its light like the soul spreads consciousness. A flame that is not burning cleanly is like a soul in maya, the state of forgetfulness of Krsna. From the soul in maya, the mind arises, like smoke rising from a flame. Smoke and flame are closely associated yet have opposite qualities: flame gives light, while smoke obscures light.
The mind is called cancala in Sanskrit, meaning 'unsteady'. Sometimes it is awake, sometimes it dreams, sometimes it is in a deep dreamless sleep. When the light of self-knowledge is obscured, wakefulness, dreaming and deep sleep delude consciousness. We therefore make such false statements as 'I think', 'last night I dreamt', 'I was unconscious', and so on.� However, the flame of the self, the soul, burns eternally, unaffected by this clouding of its light. The unsteady mind is captivated by external sense impressions. Through the mind and senses, the soul's attention is focused upon the ever-changing material world. This misdirection of consciousness (the power of the soul) turns samsara-cakra, the wheel of birth and death.
The mind, having no self-informing capacity, is misinformed by the imperfect senses. Illusioned by uncertain sense data, the mind makes mistakes. When in spite of this, we stubbornly think we've gained indubitable knowledge, we are cheated.�� For example, suppose you and I agree, on the basis of perception and logic, that 'one plus one is two' is an undisputed fact. We form a school of philosophy, the Too True To Two school. We challenge any other school to come forward and prove that "one plus one is two" is not certain. The losers have to give the winners all the money in their wallets except one banknote. A member of the One On One Won school takes up the bet. He places one drop of water on a flat glass surface with an eyedropper, then carefully adds a second drop to it. The result, to our chagrined surprise, is not two drops. We lose, cheated by our own minds and senses. After giving away the money, I have one dollar in my wallet. You have a ten dollar bill in yours. Pooling our funds, we fall into a grave philosophical contradiction. My senses tell me we now have two notes, but your mind tells you we have eleven dollars. We quarrel. I shout, 'Believe your eyes! Two!' You shout back, 'Believe your mind! Eleven!' Condemning one another, we dissolve our school.
How can we be certain about sabda?
The dispute over the two bills is not just comedy relief for readers weary of epistemology. Friction between rationalists (who believe their minds, i.e. logic) and empiricists (who believe their eyes, i.e. the senses) has been a flashpoint of regular philosophical controversy since classical times. Like unsupervised children, pratyaksa and anumana quarrel whenever the authoritative parent pramana, Vedic sabda, is absent. At the moment, anumana has more weight in science than pratyaksa. But as with all trends of history, this will not last. Stephen Hawking has this to say about the future of modern, non-Vedic anumana: 'One theory builds upon another. We can't escape the suspicion that we may be constructing a very ephemeral house of cards.' (Ferguson, 1994:65)
Unfortunately, modern intellectuals equate Vedic sabda-pramana with the sort of ipse dixit authority that Descartes rejected. And so, despite their doubts, anumana remains the favoured pramana, though it is ever uncertain. But there are three simple, standard rules of semantics (the study of linguistic communication) that, if put into practice, demonstrate the difference between sabda and ipse dixit statements, and establish sabda as authoritative. If I want to know whether a statement has real authority, I must:�
1. know what the statement means
2. know the right way to verify it
3. have good evidence for believing it (Wilson, 1960:76)
Firstly, knowing what a statement means requires me to accept an appropriate discipline of thought. For instance, I cannot know what 'nondeterministic, polynomial-time-complete' refers to through the disciplines of basket weaving, literary criticism or phrenology. The appropriate discipline is combinatorics, the study of complex logical problems. Similarly, if I want to know what the statement 'sabda is the sound incarnation of Krsna' means, I have to accept the system of discipline (parampara) through which sabda is handed down.
Secondly, I verify the statement 'sabda is the sound incarnation of Krsna' by consulting the three parampara sources of sabda: guru, sastra and sadhu. If I read this statement in sastra, I consult guru and sadhu for verification. If I hear it from guru, it is verified by sastra and sadhu; and if I hear it from sadhu, it is verified by sastra and guru.
Thirdly, there is very good evidence for believing the statement 'sabda is the sound incarnation of Krsna'. One who makes the senses and mind his authorities is bound by them, and is thus bound by ignorance of the self. In other living creatures such ignorance of the self is natural; but in man it is a vice that results in vice. The sound of Ipse dixit does not have the potency to free the self from the vicious demands of the mind and senses. Hearing it, a man remains like an animal, his life's goals no higher than eating, sleeping, sex and self-defence. Sabda that is understood and verified following the� two previous rules, transforms the hearer in a way that ipse dixit does not. As Srila Prabhupada writes in Bhagavad-gita As It Is, 'Perfect knowledge, received from the Supreme Personality of Godhead, is the path of liberation.' (Bhaktivedanta, 1983:266) Liberation of consciousness from the dictation of the mind and senses, and from ignorance and vice, is self-evident in the devotees who take to the path. And when a devotee comes to the end this path of liberation, of hearing Vedic sabda, Krsna personally reveals Himself as Absolute Knowledge, the Absolute Knower and the Absolute Object of Knowledge. This state of full realisation of the truth is called Krsna consciousness.
Ayer, A. J. The Problem of Knowledge. 1956.
A. C. Bhaktivedanta Swami Prabhupada.� Bhagavad-gita As It Is. 1983.
Davies, P. Other Worlds. 1988.
Davies, P. The Mind of God. 1992.
Descartes, R. Rule for the Direction of the Mind. 1701.
Ferguson, K.� The Fire in the Equations. 1994.
Russell, B. Problems of Philosophy. 1912.
Wilson, J. Language and the Pursuit of Truth. 1960.
Harper Collins Dictionary of Philosophy. 1992.
 Cited by Ferguson (1994: 253-4).
 Does the professor's position really represent modern science? Don't scientists have more reasonable arguments that establish logic as authoritative proof? Stephen Hawking says that quantum theory is about 'what we do not know and cannot predict'. (Ferguson, 1994:21) Ferguson furthermore notes, 'It is generally agreed that in science nothing can ever be "proved".' (Ferguson, 1994:26) About what he called 'knowledge concerning the universe as a whole',' the great philosopher-scientist Bertrand Russell (1912:82) wrote, 'the proposed proofs that, in virtue of the laws of logic such and such things must exist and such and such others cannot, are not capable of surviving a critical scrutiny.' Still, students in schools throughout the world must pass examinations on theories that scientists themselves admit are unproven. Why? The answer is that a theory is accepted not on the grounds of its certitude, but on the grounds that nobody has yet disproved it. 'The best anyone can say of a theory is that it has not been disproved.' (Ferguson, 1994:26) This principle forms the basis of modern scientific knowledge. This same principle, ironically, is considered a fallacy in classical philosophy: argumentum ad ignorantium, the fallacy of argument from ignorance. An argument that says something is true because nobody has proved it false, or that something is false because nobody has proved it true, is held to be invalid according to this rule of fallacy.
 A priori literally means 'that which precedes' (i.e. preceding sense experience). That it may mean self-evident is confirmed by the Harper Collins Dictionary of Philosophy (1992:270).