'The doctrines, Upali, of which you may know: "These doctrines lead one not to complete weariness of the world, nor to dispassion, nor to ending, nor to calm, nor to knowledge, nor to the awakening, nor to the cool" — regard them definitely as not Dhamma, not the discipline, not the word of the Teacher. But the doctrines of which you may know: "These doctrines lead one to complete weariness, dispassion, ending, calm, knowledge, the awakening, the cool" — regard them unreservedly as Dhamma, the discipline, the word of the Teacher.'
—AN 7.79 — Hare
A thing that is both misleading and stripping the Dhamma of all its magic by directing people's attention to fault finding is the question of authenticity.
Because a sutta which appears in one place is made up from ideas found individually in other places does not make either the one or the other inauthentic. It is the effectiveness of the idea in promoting freedom from pain and detachment from existence that determines it's authenticity.
It is not because a certain idea found in the Suttas was spoken by a disciple and not the Buddha that that idea is inauthentic. It is the effectiveness of the idea in promoting freedom from pain and detachment from existence that determines it's authenticity.
It is not even that an idea found completely outside of the Dhamma is necessarily inauthentic. If that idea is effective in promoting freedom from pain and detachment from existence in both its wording and spirit, then that statement is Dhamma; is to that extent the product of an awakened mind.
The idea of determining authenticity by comparison of sutta with sutta was never intended as a substitute for putting the teaching into practice. The truth of an idea, or it's effectiveness is not proven by it's agreement with ideas found in other places in the Dhamma. Such a test of authenticity is useful only where there is an outright contradiction in terminology that cannot be resolved through practice. Such a test of authenticity is found to be useful to the very beginner who is confused by conflicting statements made by commentaries, summaries, interpretations, translations and discussions and the suttas. Comparison of what is stated in a commentary with what is stated in the suttas; or what is stated as being stated in the suttas with what is actually to be found in the suttas is a valuable tool in this case. It should not be being used to whittle away at the suttas through ignorant fault-finding — pointing out contradictions which are simply changes in wording or context or (the majority) differences in translations.
But in more than 50 years of Dhamma study I have yet to find or hear of a question of authenticity based on an apparent contradiction in the Suttas that did not prove to be in stead a paradox that required only that it be resolved by an elevation of perspective. There are small insignificant errors, there are crude editings, there are contradictions in names and places, but this is not what is intended when speaking of comparing sutta with sutta: what is intended is the comparison of the doctrine being espoused.
Again, it is not because a certain sutta contains phrases that are older than another sutta that makes the one authentic and the other inauthentic. The suttas were collected from the very first and the four official collections were an early aspect of the life of the bhikkhus and were in the charge of the highest level of Gotama's followers. Over the period of their collection (which spanned from the beginning of Gotama's teaching to well beyond his death) suttas were added when they were uttered, found or remembered. Early and late were intermixed early and late as was dictated by the various organizations of the baskets. The four baskets were made so as to be redundant within themselves and across the Nikayas in different, independent ways. When a new sutta was added, it, or its ideas, were incorporated into each of the four Nikayas in different ways. This was a matter of preserving the ideas in the dhamma.
It is not a proof of inauthenticity that a sutta is missing or present in the Pali when it is present or absent in the Chinese or Sanskrit or Tibetan or in one collection or another or the reverse.
It is not a proof of inauthenticity that a sutta or a part of a sutta is in one order in one collection and in another order in another collection.
It is the effectiveness of the idea in promoting freedom from pain and detachment from existence that determines it's authenticity. That is the only criteria that is useful and not a waste of time.
Further, the idea that what we have in the Pali is not the language of the Buddha is absurd. It should be dismissed by any rational thinking mind. For that to be the case the whole of the Dhamma as we have it would have required translation from Gotama's spoken language into the Pali and that from the very first and by a continuous coherent body of translators as wide-awake as the Buddha himself and not by the various groups and individuals to whom we know the suttas were actually delivered. We can see the mess that has been made of the effort to translate the Pali into English, which is for the modern translator conveniently in written form with it's consistent terminology and ideas already worked out for him. It took more than a hundred years just to complete the first translation of the four Nikayas and there is still no translation which has a consistent vocabulary (and therefore construction of a consistent Dhamma) across the entire four nikayas. As mentioned previously, memorization began during the lifetime of the Buddha; is it being said that the translation too began during his lifetime? If so or if not, at what point, and by whom, and how is it that such a monstruous project is nowhere mentioned? And how is it that the Four Nikayas maintain such consistency? It is preposterous; it is beyond reasonable to maintain this idea. There may have been editing and errors around the edges, but the Dhamma within is consistent and employs massive redundancy which acts to scour out wrong doctrine; such consistency could only have been maintained by an awakened Buddha or Arahant and the arahant would never alter word or spirit of the Teacher or have had any reason to translate it from one vernacular to another.
The idea that the language of the Buddha was different than the Pali is suggested by the theory that the Pali came after the Vedic and Sanskrit and that traces of supposedly older prakrits, or spoken languages are found here and there in the Pali. Leaving open the idea that language begins perfect and complex and deteriorates into common language defies reason, there is no reason to think that what we have in the Pali is not an artificial language in the sense that of the terms in common use in the Time of Gotama, Gotama selected those which most concretely expressed his ideas and that among those were some of the oldest terms known as well as some that were more modern, and that, just to be safe, they were all defined internally. We could, and translators of the Pali really should, do the same thing with English.
It is the nature of the Pali that it is so constructed as to be comprehensible across Time, Culture and state of consciousness such that it is possible to translate it in a great vareity of ways that are more or less completely consistent across its entirety and which cannot but be called true or correct translations but which will produce as a result a Dhamma which is strictly limited to a certain strata of reader.
Such is the case, for example, in the translation of 'dukkha' as 'stress'. It is possible for the well-educated American-English speaker to understand this term as applicable to aging, sickness and death; grief and lamentation; pain and misery; and despair. It is also subject to being misunderstood by those who do not both understand the aim of the Dhamma and the scope of the intended use of this term. One result is an industry riding on the authority of the Buddha that makes money from teaching businesses how to reduce stress in their employees. Another is the emergence of a class of Buddhists that view the scope of the Dhamma in strictly worldly terms; as a practice aimed predominantly at bringing one success and happiness in this world. There are similar objections to the use of 'anxiety' 'angst' and even 'suffering' (the laboring classes do not admit they suffer). 'Pain' works across Time and State of consciousness for English speakers. The gods would have a hard time understanding the term. 'Shit' is understood across Time, Culture, and State of Consciousness and can be pointed to where even the very clear connotation and near universal meaning of the sounds do not come across clearly.
Authenticity in this sense can only be claimed by the original Pali. Do not make the mistake that is found throughout the web of arguing a point based on translation or worse of confusing the terms of one translation with those of another. Again: there is no set of translations out there today that is consistent in its terminology across the whole of the suttas.
You need to understand why you are interested in becoming a Buddhist. If you are simply seeking a rudder to keep you on a steady ethical course in the madness of this world, you have found a good rudder, but do not mistake your satisfaction at the rationality of the Dhamma in this area for the full scope of its purpose.
Similarly you may be seeking success in this world through skillful manipulation of kamma. Again you will find a consummate guide in the Dhamma for that purpose, but again, do not mistake that success for the purpose of the Dhamma.
The Dhamma was intended, over and above all as a method for escaping kamma, escaping the endless cycle of rebirth.
To achieve this end you need to understand that this study needs to become your primary interest in life and that it is, baring the fact that you are some sort of genius or have arrived here in some advanced state because of hard work done in a previous life, going to take you the rest of your life to get to any degree of accomplishment in the system and it will be the hardest task you have ever put yourself through. Then you may understand:
Beggars! The best course does not have a gains-honour-reputation-core,
nor an accomplishment-in-ethics-core,
nor a accomplishment-in-serenity-core,
nor a knowledge-vision-core.
But there is beggars, unshakable heart-release —
here, beggars the best course is for attainment of this.
This is it's hardwood.
This is it's encompassing end.
Is the Satipatthana Sutta Inauthentic?
In [AN 6.29] The Buddha asks Udayi about the five establishments of memory and gets a wrong answer. Then he asks Ānanda the same question and gets a satisfactory response.
Note the similarity of several passages with those found in the Satipatthana Suttas MN 10; DN 22. One could definitely piece together the entire Satipatthana verbatim from passages in the Anguttara and Samyutta Nikayas. This, together with the understanding that the Satipatthanas are called 'Suttanta', or 'Collection of Suttas' would argue strongly against the conclusion that the Satipatthanas were first created whole and then later raided for parts. The Satipatthanas may well have been spoken as they are found by Gotama as collections of earlier bits, but the disjointed 'feel', the lack of symmetry (e.g., some parts have similes and some not), of the four divisions would suggest a compilation by someone other than Gotama either before or after his death. Who knows? It is not important. The content is True Dhamma no matter what. True Dhamma is determined by the message, not the reported speaker or time it was delivered or language in which it was delivered. The problem with works such as the Mahayana suttas and some parts at least of the Abhidhamma is that they preach a message contradictory to the goal as found in the suttas while claiming to be the word of the Buddha. Then it is useful to point out that they were composed centuries after Gotama's death and that it is a contradiction of Dhamma to claim that he returned to deliver such messages when the entire point of the system is not returning. That is misleading. To point out the misleading nature of some doctrine is True Dhamma. Otherwise one should not get wound up in such issues. One could spend lifetimes digging around in the suttas trying to determine the truth of such things and end up hardly moving ahead at all towards the goal.
See also: [AN 4.180] A well-known (and too little used) sutta.
The Buddha tells the bhikkhus to determine whether or not a saying is to be considered as his word by comparing the phrases and their construction
padavyañjana: pada: phrase;
vyañjana, lubrication, component parts;
Woodward: 'words and syllables';
Bhk. Bodhi: 'words and phrases'.
The precise meanings of this phrase is worth a deeper look.
'Pada' is literally 'foot', Pāda 'footstep' or 'path'.
In the spoken language the 'letter' was a syllable, and the bhikkhus were on occasion remarked to take pride in repeating Gotama's word 'down to the syllable', but vyañjana means 'letter' only in the sense of 'as opposed to the spirit'.
It does mean component part and derives from the idea of lubricant (enabling the letters to work together and make sense) and stretching out, drawing out or erecting, i.e. the construction of the phrase) with the phrases and their construction as found in the Suttas and in the Vinaya.
This is to be done even in the case of four great authorities:
Someone who has reportedly heard a saying face-to-face with the Buddha;
some Saŋgha with a reportedly learned elder;
some reportedly learned Saŋgha;
a single reportedly learned monk.
Today this is taught with the idea that we are to accept it as the word of the Buddha if it comes from any of these four 'authorities'.
This is exactly the opposite of the meaning found in the sutta.
We should also add that this work of comparison should be done with any reportedly true saying heard from any 'authority' or read about (including any translation from the Pali) in any book or anywhere on the internet.
'Any' includes 'is'sef 'ere.
 See AN 4.6 This sutta has in it an unmistakable work of later editing in the list of works that are supposed to be read by one who is to be called well read (having 'heard much'). The list includes books known to be much later in origin than the Suttas. This is both discouraging and hopeful. It is discouraging because seeing work of this sort it is clear that there was some tampering with even the suttas. It is discouraging because it has tainted this work with bias (the desire to have works that are not original documentation considered as original documentation) and allowed in doubt. It is hopeful because it shows the childish stupidity of the tamperers. They could not see that it would be easy to see what they have done. What they do is always clumsy and obvious and consequently if one keeps alert they will not lead one astray. (But clearly they have already lead many astray!).
 See for precisely the wrong approach (ok, at least an approach which does not make good sense when one asks 'Why?' would such an artificial language be constructed, and could the 'How?' be different than the accepted academic theory) to thinking about Pali as an artificial language: O. von Hinuber, Pali as an Artificial Language From Indologica.com, The Online Journal of the International Association of Sanskrit Studies, Volume X (1982), Proceedings of the "Conference-Seminar of Indological Studies", Article #10. PDF
See: SN 4.44.7 The Wanderer of the Vaccha Clan asks Maha Moggallāna a series of questions about existence and non-existence and is told in all cases that these are not questions on which the Buddha has made a declarative statement. When asked why this is so, Maha Moggallāna explains that it is only because of holding views about the self with regard to the senses that these questions arise and that not holding such views the questions do not arise. Vaccha then goes to the Buddha and puts the same questions and receives the same answers.
This is one of the places which I have here and there mentioned where the bhikkhus themselves, at the time, remark on the fact that both disciples and the Buddha use the same wording and phrasing when responding to the same questions. I suggest this is because the most precise wording and phrasing with regard to questions and answers has been worked out and so is not a matter of remembering what the Buddha Said, but of responding in accordance with the most precise understanding. I further suggest that we can and should find such precise wording in our English translations and that that is the way the doctrine will be most profitably understood.
MN 30 Discussion illustrating how a paradox should not be mistaken for an error or editorial tampering.