Smoking cigarettes-Is it permitted according to Halacha:
A. The law:
There is no innate Halachic prohibition against smoking tobacco. The act of smoking tobacco is mentioned in numerous Poskim in regard to various Halachic matters, and was done by Gedolei Yisrael of many generations as well as the average folk. It was even considered healthy to smoke, and satiates one as if he ate food, and was considered to contain medicinal benefits. Nevertheless, due to the discovery of the lethal cancerous effects involved in smoking today’s cigarettes, the vast majority of today’s Poskim hold it is Biblically forbidden to smoke cigarettes due to the command of “Vinishmartem Meod Nafshoseichem.” Furthermore, writes the Chofetz Chaim, that one who weakens his body and health by smoking will certainly be brought to judgment on this for destroying the body that G-d gave him to serve Him. Nevertheless, some Poskim maintain that even today, despite the health hazards, smoking remains permitted, although it is advisable to abstain from doing so.
One who already smokes: Some Poskim rule that one who already is addicted to smoking does not transgress the above command.
B. Smoking in public and the Rebbe’s opinion:
Coming up in part 2!
 See Sefer Shemiras Hanefesh; Encyclopedia Hilchatit Refuit “Ishun” Vol. 6 p. 263
 Regarding saying a before blessing prior to smoking: M”A 210:9 [Tzaruch Iyun] Mor Uketzia 210 [no]; P”M 210 A”A 9 [no]; Chasam Sofer on O.C. 210; Regarding lighting a cigarette from a non-Kosher candle: Peri Chadash Y.D. 108; Machazik Bracha 210, Masas Moshe Y.D. 4; Chasam Sofer on O.C. 210; Regarding if one may light it from a Shul’s candle and smoke in Shul: Shaareiy Teshuvah 154:20; Regarding smoking on Yom Tov: P”M 511 and Pnei Yehoshua Shabbos 39; M”E 599:1; Shaareiy Teshuvah 511:5 in name of Machazik Bracha; Sefer Haminhagim p. 117 [English]; Igros Kodesh Rebbe Rayatz 4:132; 6:429; Otzer Minhagei Chabad p. 53; regarding smoking on a fast day; Shaareiy Teshuvah 210:9 regarding various of the above issues; Regarding smoking on Pesach: Admur 467:24
 Machaneh Efraim and Rabanan Keshishaiy [Shaareiy Teshuvah 210:9]; Shivchei Habesht that the Baal Shem Tov was said to smoke on Saturday nights and whenever he desire to experience a spiritual elevation; Rav Chaim of Tzans would smoke; The Rebbe Rashab smoked, as brought in his Igros Kodesh and Toras Menachem 1:6
 M”A 210:9
 P”M 210 A”A 9; P”M 511 M”Z 2; Pnei Yehoshua Shabbos 39; Mur Uketzia O.C. 511; Karban Nesanel Beitza 2:22-10; Shaareiy Teshuvah 210:9; Kesav Sofer O.C. 66; Levushei Mordechai Basra 105; Zecher Yehosef 198
 First entertained in 1761, and later published with medical proofs in 1854. It was not until the 1950s that the discovery was made that smoking cigarettes can cause lung cancer. In 1958 through 1968 the United States Public health service publicized statistically based proof of the dangers of smoking cigarettes and of the high mortality rate that it causes
 Amudei Or 29; Mishneh Berurah in Likkutei Imrim 13 and Zechor Lemiryam 10:28; Toras Habayis 4; Hashabit 3:134; Tzitz Eliezer 15:39; 17:21-22; Beir Moshe 6:160-9; Shevet Hakehasi 1:332; Shevet Halevi 10:295; Teshuvos Vehanhagos 3:354; Dibros Eliyahu 6:105; Halichos Olam 1:266; Rav SZ”A in Minchas Shlomo 2:58-6; Nishmas Avraham 240:1; Yechaveh Daas 5:181 and Halichos Olam 1 Vayikra; Rav Bentzion Aba Shaul Chochma Umussar p. 221; Asei Lecha Rav 1:42; 2:1; 3:18; 7:67; 9:28; Rivivos Efraim 8:586; Poskim in Encyclopedia ibid footnote 94
 The reason: As one is obligated to guard his life from health hazards. This is a Biblical obligation. [Admur Shemiras Guf Vinefesh Halacha 3 and 14 “One is obligated to beware of his body, to not cause it loss, destruction or injury.”; Michaber 427:8; Rambam Rotzeiach 11:3; Implication of Brachos 32b and Maharsha there Shavuos 36a; Levush Ir Shushan C.M. 426:11 [Unlike Levush Y.D. 116:1-See Darkei Teshuvah 116:57]; Tevuos Shur 13:2; P”M O.C. 4 A”A 2; Y.D. 97 S.D. 3; Noda Beyehuda Tinyana Y.D. 10; Chidushei Chasam Sofer Avoda Zara 30a; Minchas Chinuch Mitzvah 546; Chochmas Adam 68:4; Chayeh Adam 15:24; Shoel Umeishiv Tinyana 3:122; Aruch Hashulchan C.M. 427:8; Marcheshes 20; Mishmeres Shalom 108; Beis Yehuda Y.D. 25; Zivcheiy Tzedek Y.D. 116:4; Avnei Tzedek Y.D. 49; See Minchas Chinuch Mitzvah 546; Shemiras Hanefesh Kehilchasa Chapter p. 19; Shemiras Haguf Vihanefesh [Lerner] Mavo Chapter 1; See in length Encyclopedia Hilchatit Refuit Erech Berius Vol. 2 pp. 352-355]
Other opinions-This command is merely Rabbinical: Some Poskim rule that there is no Biblical command to guard one’s safety and that it is merely a Rabbinical injunction. [Possible implication of Michaber ibid who rules a transgressor only gets Makas Mardus; Levush Y.D. 116:1; Beir Hagoleh C.M. 427 Ayin leaves this matter in question; Shivim Temarim Ayin Daled 1, 4 writes that it is merely Rabbinical and that the verse is a mere Asmachta; Rabbeinu Yerucham Nesiv 15:30; Semak 171; Divrei Malkiel 4:62]
 Chofetz Chaim in Kuntrus Likkutei Imrim chapter 13
 Devar Shmuel 156; Igros Moshe Y.D. 2:49; [see also C.M. 2:18, 76]; Rav Elyashiv in Kovetz Am Torah 2:3 and Koveitz Teshuvos 219; Az Nidbaru 9:65; Mishneh Halachos 9:161; Beis Avi 4:9-3; Rav SZ”A in Nishmas Avraham O.C. 511; See Yalkut Yosef Kibud Av 2:55; 3:216-12; Poskim in Encyclopedia ibid footnote 99; See Shevet Halevi 10:295
 The reason: As any matter which the public is accustomed to doing, even if dangerous, Hashem guards and saves them. [Shabbos 129b regarding Erev Shabbos; Yevamos 12b and 72a; Kesubos 39a; Avoda Zara 30b; Niddah 45a; Sanhedrin 110] And the same applies regarding cigarettes. [Igros Moshe ibid; See Encyclopedia ibid; Ben Poras 11; So rule regarding talking while eating: Perisha 170:1; Elya Raba 170; Shaareiy Teshuvah 170:1; However, see Igros Kodesh 2:143]
 Dibros Eliyahu 127
 The reason: As whoever knowingly transgresses a Biblical command is invalid as a witness. [Michaber C.M. 34:1-3; Sanhedrin 24] Now, although one who does a transgression due to ignorance of the prohibition involved is not invalid for testimony [Rama 34:4] nevertheless, regarding smoking, everybody knows that it is dangerous for one’s health.
 Mishneh Halachos 9:161; See Yalkut Yosef Kibud Av 2:55-56