[1][2][3] Born in Smorgon before relocating to Ilya, he shifted from focusing on the Talmud to secular sciences and learning such as higher mathematics.

[4] Manesseh was a conservative and a humanitarian, expressing ideas of unity and cooperation in secular and Jewish learning.

In his 1807 Pesher Dabar, he wrote:[8]"...the Jews are divorced from real life and its practical needs and demands; that the leaders of the Jews are short-sighted men who, instead of enlightening their followers, darken their intellect with casuistic restrictions, in which each rabbi endeavors to outdo his predecessors and contemporaries.

Elijah, the Gaon of Wilna, his teacher, found out that Manasseh had met with Shneur Zalman of Liadi and suspected him of Hasidic tendencies, which he denied although he did sympathize somewhat with that movement.

[8] He was friends with Judah Loew ben Bezalel, Samuel Eliasberg, and Wolf Adelsohn.