These two quotes speak for themselves. They were written many decades ago, but apparently we have not learnt from them.

The Netziv writes in Ha’amek Davar in the introduction to Bereishis:

The praise ‘straight’ (yashar) is said about the justice of G-d’s judgment in the destruction of the Second Beis Hamikdosh because the generation were perverse and twisted. We have explained that even though they were tzadikim and chasidim and toiled in Torah, nevertheless they were not straight in their dealings with the world. Because of their hatred for each other, anyone who didn’t serve G-d according to their opinion was suspected of being a Saducee or an apikoros. Through this they came to murder through their arguments, which led to all the bad things in the world, until the Beis Hamikdosh was destroyed.

In other words, baseless hatred means invalidating someone else’s worldview or hashkafa! Let’s both be right, and agree that there is more than one correct Jewish path to serving G-d!

This is what the Chofetz Chaim writes about posting flyers and letters against others with whom we disagree (it is letter number 31 in his ‘Letters’ in the complete works of the Chofetz Chaim)

I must speak out my heart about the manner of conflict taking place among the Jewish people. One camp publicizes its view in the newspapers with the signatures of all of its backers. The other side does the same. One of them wrote ‘the one with the most signatures wins’, and I say the one with the most signatures is creating unnecessary conflict in Israel. All of Israel is burning like a fire as each side places more and more ads condemning their opposition. Even the holy land of Israel is becoming a subject of controversy. I don’t know who permitted all of these terrible sins. Everyone is sure that he is saying the truth and it is the other opinion that is creating the argument. This is a grave error, because even if both are right, they have no right to violate the Torah. So many mitzvos are being violated. No good can possibly come out of this. Right or wrong, they are creating a chilul Hashem desecration of G-d’s Name. Twenty-four thousand students of Rabbi Akiva died in one month, not because they argued, but because they argued improperly and caused a chilul Hashem. Certainly each one of these giants felt that he was right.

Everyone is going to hear divrei Torah about the evils of lashon hara at this time. The Chofetz Chaim is being quoted by everyone – but I don’t remember ever hearing this letter quoted. (If you look at the original you will see he is even harsher than the extract translated here!)

For more sources on Tisha B’Av you can go to www.torahlab.org and download a free source sheet and teachers’ guide.

May we merit to greet Mashiach very soon, and let us learn from the gedolim of the past generations.