There is a well-known Halacha codified in the Shulhan Aruch (Orah Haim 141) that a congregation should not call a father and son for successive Aliyot to the Torah. Several different reasons have been suggested for this Halacha. The Maharam of Rotenberg (Germany, 1215-1293) explained that calling a father and a son for Aliyot one right after the other may cause an Ayin Ha’ra ("evil eye"), and therefore congregations who wish to give Aliyot to a father and son should separate the Aliyot.
A different reason is offered by the Orhot Haim (Rabbi Aharon Ha’kohen of Lunel, 1280-1330), who notes that the Torah is sometimes referred to as "testimony" (as in the famous verse, "Edut Hashem Ne’emana" – Tehillim 19:8). Reading the Torah is thus akin to submitting testimony, and just as a father and son may not testify together, similarly, they should not read the Torah one after the other.
There are many questions that could be asked regarding the Orhot Haim’s explanation. The Vilna Gaon (Rabbi Eliyahu of Vilna, 1720-1797), for example, noted that theoretically, Halacha allows calling children and women for Aliyot to the Torah (though practically speaking, this is not allowed for technical reasons), despite the fact that they are clearly disqualified from rendering formal testimony. Clearly, then, suitability for an Aliya does not depend upon suitability for formal testimony.
Be that as it may, the Orhot Haim’s theory forms the basis of a ruling of the Peri Megadim (Rabbi Yosef Ben Meir Teomim, 1727-1792), that a congregation should not call intentional Torah violators for an Aliya. Since willful Torah violators are disqualified as witnesses, they also should not be called to read from the Torah. The Peri Megadim cites this ruling from the work Besamim Rosh. This is also the position taken in the work Megaleh Amukot, who writes that a person who shaves with a razor – which is a grave Torah violation – should not be called for an Aliya to the Torah.
The Ben Ish Hai (Rav Yosef Haim of Baghdad, 1833-1909), however, disagrees. He writes that if we would begin making inquiries into a person’s spiritual standing before agreeing to call him for an Aliya, this would create destructive strife and discord in the synagogue. This is especially true, he adds, in the case of respected, upstanding members of the community who would be refused Aliyot because of various allegations. We certainly do not want to create such tension and friction in the synagogue, and therefore we should not "investigate" congregants before calling them for an Aliya.
Hacham Ovadia Yosef, in his work Yabia Omer (vol. 10), follows this ruling of the Ben Ish Hai, and writes that congregations should call people for Aliyot without inquiring into their spiritual standing. He adds, however, that if a person publicly desecrates the Shabbat, he should not be given one of the seven principal Aliyot on Shabbat. If a congregation wishes to give him an Aliya, they should add an extra Aliya and call him for that Aliya. Generally speaking, however, a person may be called for an Aliya even if he is not fully observant. It might even be advisable to specifically invite violators for an Aliya for the section of the Torah that discusses the Misva they ignore. For example, if a person shaves with a razor, it might be a good idea to call him for the Aliya in the Book of Vayikra that speaks of this prohibition. And if somebody commits sins of Arayot (sexual immorality), he should specifically be shown the section in the Torah outlining the prohibitions of Arayot, and so on, as this may inspire him to perform Teshuba.
Summary: A person may be called to the Torah for an Aliya even if he commits sins. If he is a public Shabbat violator, then he should not be called for one of the seven basic Aliyot, but an extra Aliya may be added for him to receive an Aliya.
