Over at VosIzNeias there is a report of a dove that flew into the Kaminetz Yeshivah and wouldn't be dissuaded from returning every day. Inevitably, people are talking about it being a gilgul.
I'm not going to denounce this belief. There are many bloggers who see it as their "holy" mission to criticize or mock other people's beliefs which they see as irrational or otherwise mistaken. But although people certainly differ in the extent to which they are rational, everyone in the world has some irrational beliefs, be it in the sphere of religion or elsewhere. Furthermore, personally I rarely see any constructive purpose in criticizing or mocking the beliefs of others; such pursuits are usually just about putting others down to make oneself feel big. So if people want to believe that the dove is a gilgul, then, as we used to say, gezunte heit! Live and be well. I don't think that people are harmed by such things.
But in the comments section of the ViN post, the argument about gilgul turns ugly. After one person mentions that Chazal and the Rishonim did not believe in such things, another person responds that the Zohar mentions it and anyone who denies the Zohar is a heretic. And actually the first person already raised the stakes to kefirah, quoting Saadiah Gaon as maintaining that belief in gilgulim falls into that category.
Why can't we all just get along? As is well known, there have been many rabbinic authorities who subscribed to belief in gilgulim. On the other hand, there have also been numerous opponents to this belief, including Rav Saadiah Gaon (Emunos v’Dayos 6:8); Rabbeinu Avraham ben HaRambam (see R. Margoliyos, in his introduction to Milchamos Hashem p. 19 note 11); Rabbi Avraham ibn Daud (Emunah Ramah 7); Rabbeinu Yitzchak ben Avraham Ibn Latif (Rav Poalim, p. 9 section 21); Rav Chasdai Crescas (Ohr Hashem, ma’amar 4, derash 7); Rav Yosef Albo (Sefer HaIkkarim 4:29); and Rav Avraham Bedersi (Ktav Hitnatzlut leRashba). See too Rashash to Bava Metzia 107a (I am told that certain Chassidim will never study Rashash because of his comments on this topic). Also see Rabbi Samson Raphael Hirsch, commentary to Genesis 50:2. For further discussion, see Rabbi Yitzchak Blau, “Body And Soul: Tehiyyat ha-Metim and Gilgulim in Medieval and Modern Philosophy,” The Torah u-Madda Journal vol. 10 (2001).
If someone does not share your belief regarding the existence/non-existence of gilgulim, just let them be! Is it really necessary to denounce other people as heretics or fools? Just be aware, and politely inform others, that there have been many Torah authorities on both sides of this issue.
On a lighter note, I was told a terrific story by someone who studied at Gateshead yeshivah in England. A bird once flew into the Beis HaMidrash, and someone approached the Rosh Yeshivah and said, "Efsher it's a gilgul?"
Replied the Rosh Yeshivah, "Efsher it's a feigel?"