The principal claim of the essay is that sentiments and assumptions about senti-ments– have an important role in setting up constitutional designs and interpretation (“evolvingstandards of decency”);– constitutional arrangements do have impacts on social emotions;– the disregard of the interrelation of emotions and other forms of cognition condemnslegal theory to one-sidedness and the efforts of behavioral economics seem not to undo thisone-sidedness.For example, fear is present in the making of many constitutions. Constitutions aredesigned to give assurances against fear that stems from, among others, pre-constitutionaloppression, mob rule and factional passions. Constitutional rights are also structured byemotions: Compassion and indignation serve as emotional grounds to accept and claimhuman rights.A simplified vision of modernity claims that law and constitutional design is all aboutrationality. Brain imaging studies indicate that moral emotions guide many moral judgments orare in competition with reasoning processes. Of course, moral emotions contribute to theshaping of law through moral judgments. To the extent law intends to shape behavior, it willrely on its legal folk psychology. A theory of constitutional sentiments shall reconstructthe assumptions on human nature as emotional nature that shape the constitution and itsinterpretation.Historically, constitutional path dependence presupposes emotional choices and emotionalaction tendencies that are institutionalized and ‘imposed’ on law and society. Paradigmaticchanges in constitutional law cannot be explained without considering the path-breaking ruleof emotions. For example, the commitment to abolish slavery cannot be explained without theemotional condemnation (based on disgust and resulting in indignation) of the institution. Theban on torture is also rooted in sentiments of disgust. Concepts of cruel and unusual punish-ment are rooted in emotions of disgust. Law is both trying to script emotions (in order toprevent challenges to the status quo) and accommodates prevailing (or preferred) emotions(hence the difficulty of a non-revenge based criminal policy)