Christopher Langston

Loss of personal identity in dementia can raise a number of ethical considerations, including the applicability of advance directives and the validity of patient preferences that seem incongruous with a previous history of values. In this chapter, we first endorse the self-concept view as the most appropriate approach to personal continuity in healthcare. We briefly describe two different types of dementia, Alzheimer’s dementia (AD) and behavioral-variant frontotemporal dementia (bv-FTD). We identify elements considered important for the continuation of a self-concept, including continuation of memories, consistency in personality traits and personal preferences, and continued endorsement of certain moral tenets. We show that, depending on which element is considered most important for personal identity, continuity of a self-concept for individuals with distinct types of dementia will be affected and assessed differently. Utilizing a variety of empirical evidence, we argue that persistence of memory, personality traits, and preferences are not the most important for the maintenance of personal identity. Instead, as studies aimed to capture the folk-psychological view of personal continuity demonstrate, judgements about continuity depend primarily on the persistent commitment to widely shared moral beliefs. Because of that, we argue that individuals with bv-FTD are more likely to lose their sense of self than individuals whose dementia primarily affects memory, such as Alzheimer’s disease. We end the chapter by showing how the importance of moral beliefs for continuity of self can be used to provide guidance to health-care professionals when considering changes in preference by individuals with dementia.

A number of theoretical positions in psychology—including variants of case‐based reasoning, instance‐based analogy, and connectionist models—maintain that abstract rules are not involved in human reasoning, or at best play a minor role. Other views hold that the use of abstract rules is a core aspect of human reasoning. We propose eight criteria for determining whether or not people use abstract rules in reasoning, and examine evidence relevant to each criterion for several rule systems. We argue that there is substantial evidence that several different inferential rules, including modus ponens, contractual rules, causal rules, and the law of large numbers, are used in solving everyday problems. We discuss the implications for various theoretical positions and consider hybrid mechanisms that combine aspects of instance and rule models.