It has been noted that after the Rambam’s Mishneh Torah, halakhic codes did not include fundamental beliefs. This, it is claimed, implies that halakhists rejected Rambam’s view that these beliefs are obligatory and that there are negative implications for those who fail to accept them. This is wrong.
In the introduction to the Sefer Ha-Chinukh, the author lists six constant commandments: 1) to believe in God, 2) to believe in God’s unity, 3) to love God, 4) to fear God, 5) not to believe in other gods, 6) not to stray after your eyes and your heart. The Chinukh was unquestionably influenced by the Rambam (as pointed out by Menachem Kellner’s wife Jolene in his Must A Jew Believe Anything?, p. 16 n. 6). These obligations include some of the Rambam’s 13 fundamental principles
Click here for moreThese six constant commandments are listed in the halakhic code Chayei Adam (ch. 1). Following his lead, the Mishnah Berurah also lists these six commandments (ch. 1, Bi’ur Halakhah sv. hu). Both of these important codes evidently show the influence of the Rambam by obligating belief in these fundamental concepts.
Surprisingly, the Kitzur Shulchan Arukh does not follow the Chayei Adam on this and omits the six constant commandments. However, the She’arim Metzuyanim Ba-Halakhah commentary to the Kitzur (1:1) corrects this lacuna. Similarly, R. Gersion Appel lists these six commanded beliefs in his The Concise Code of Jewish Law (vol. 1, pp. 2-5).
Perhaps most importantly, the Arukh Ha-Shulchan (Orach Chaim 1:5-14) quotes the six constant commandments and adds other fundamental beliefs — such as belief in the Written Torah and Oral Torah, belief in reward & punishment and the messiah — and specifically labels them as fundamental beliefs.
I believe that all of these examples show that important halakhic codes confirmed the Maimonidean concept of commanded beliefs. And the Arukh Ha-Shulchan even shows the acceptance of fundamental beliefs.
Of course, the idea of fundamental beliefs can be found in the Shulchan Arukh as well. See Choshen Mishpat 34:22, 425:5 and Yoreh De’ah 268:2. I discuss these examples in more depth in my article “Crossroads: Where Theology Meets Halacha” in Modern Judaism 24:3, pp. 279-282 (link).