Words of the Buddha

This question is motivated by a comment from another user . Highlights in the quote are made by me. It's written: > "**You have no reason to believe that any words of the Buddha are preserved except uncritical acceptance of traditional narratives. There are some Buddhist words, but to attribute them to the Buddha is simple, blind religious faith**. If your criteria is practical application, then your question is meaningless in any case. You can verify the truth of the quotations by putting them into practice. Why have you not done so?". My questions are: - What reasons are there for believing that the words of the historical Buddha are preserved? - What reasons are there for not believing that the words of the historical Buddha are preserved? - Do these reasons apply equally to all "words" or, for example, is it more believable of the suttas than of the Jataka tales, or of some suttas more than others?