The Duties of the Heart, by Rabbi Bachye, tr. by Edwin Collins, [1909], at sacred-texts.com
The Duties of the Heart are more Important than any others
The obligation to fulfil the duties of the heart and mind is greater than any other, for, whether they
refer to the commands of Reason, or to those of Scripture or of Tradition, they are the foundations of all the precepts; and if there chance to be even the slightest failure in the ethics of the soul, there can be no proper fulfilment of any external ethical duty.