Do Not Be a Fool
Simcha
Rav Henich often quoted his teacher Rav Simcha Bunim of Peshischa: "By us, all the negative commandments in the Torah can be condensed to one negative commandment, 'Do not be a fool,' and all the positive commandments in the Torah can be encapsulated in one, 'Be wise.'"
Source: Quoted in the name of Rav Simcha Bunim of Peshischa