A bad drasha starts with the insight and contrives textual corroboration as an afterthought. The intent of the former is understanding. The intent of the latter is to use the text as an approbation for an idea conceived independent of the text. For example:
Rabbi Abba Bar Shmuel said: For three years The House of Hillel and The House of Shammai argued. One side said ‘The law is like us!’ The other side said, ‘The law is like us!’ A heavenly voice came forth and declared: These and these are the words of the living God, and the law should be decided as Hillel says!
But after it is declared that these and these are the words of the living God, why did the House of Hillel merit having the law decided like them? Because they were gentle and humble and they would teach the words of the House of Shammai, not only would they teach their words, but they would quote Beit Shammai before they would give their own opinions. (B. Talmud Eruvin 13b)
I can't tell you how many times that the agreeing to disagree of Hillel and Shammai are brought to "prove" that pluralism has always been part of our tradition. This is not an honest reading of Hillel and Shammai, or the heavenly voice who endorsed both of their opinions. Hillel and Shammai both agreed on the Divine authority of the Torah. They often disagreed on how to interpret it. Much like Supreme Court justices who believe in the integrity and authority of the Constitution, but disagree on what it means.
This is a plurality of opinion, but it's not our pluralism. Our pluralism means that everyone respects each other even though they agree on virtually nothing--not even whom is considered to be a Jew. This source has nothing to say about that kind of pluralism and therefore would never challenge a traditional thinker to be more open minded regarding others. It might, in fact, have the opposite effect. Because the insight preceded the text, the text does not prove the insight, and therefore this qualifies as a paradigmatic example of a bad drasha.
Does this mean that there are no sources that might challenge a traditional thinker? No, it just means that if one wishes to challenge someone on their own terms, he needs to do so with their tools and not rush to super impose his values on an ancient text. For example:
A simple understanding of this statement is that even though truth is the seal of God, nevertheless, it takes a back seat to peace. It is worth sacrificing truth in favor of harmony, for this is what the Torah did for Sarah, so that Abraham would not be angry at her. This source allows one to interact with perceived heretics for the sake of peace which is a greater value. This is not because one acknowledges the other's truth, but because it is better to get along than it is to be belligerent. It may or may not be a religious imperative, but it is an honest reading of a text which cannot be easily dismissed. It also doesn't give the pluralist everything he wants because what he wants is a modern value that does not exist in traditional sources.
How great is peace, that even the Torah misrepresented Sarah's words in order to bring harmony between Abraham and Sarah , as it is written, “And Sarah laughed quietly saying after I have been without season and my master is old.” Later when the story is repeated the narrative changes, and instead of “my master is old” it says, “and I [Sarah] am old.”( Derech Eretz Perek Shalom)
It is, however, a step forward and the most honest approach given the differences that we face. If getting along in spite of formidable differences is a religious, read Orthodox value, the nature of discourse could be fundamentally transformed.
For the Hebrew sources, a translation and commentary on both texts for downloading, click here.