How can one determine which parts of the Buddhist scriptures are authentic and which may be later interpolations?

In this answer , a user writes: > The Buddhist scriptures attributed to the Buddha contain > contradictions, obvious frauds, obvious later-day insertions, etc., > therefore there can be no scriptural authority in Buddhism; apart from > what can be verified for oneself as being true & real that leads to > the ending of suffering. This raises the question:- How can one objectively determine which parts of the Buddhist scriptures, particularly the suttas are likely to be original teachings of the Buddha, and which may be later interpolations or corruptions? What criteria are used in this process? Are there scholarly or traditional methods that help identify interpolations, such as historical analysis, linguistic patterns, consistency with core teachings, or comparisons across early textual traditions? Additionally, how can we be sure that what some modern practitioners or scholars label as later additions were not already part of the original oral tradition? Why could some of these elements not be understood through reinterpretation rather than being dismissed outright? Are there critical editions of the suttas or major academic resources that address this issue? I am interested in perspectives based on traditional commentaries, scriptural analysis, and modern scholarship.