Character plays a central role in our everyday understanding and evaluation of ourselves and one another. It informs the expectations that ground our plans and projects, our moral responses to other people’s behaviour and to opportunities we ourselves face, and our political decisions concerning formal education, criminal punishment, and other aspects of social organisation. The very idea that people have persisting character traits that explain their behaviour is woven throughout the fabric of our culture. These philosophical essays clarify this idea of character, analyse its relation with the findings of experimental psychology, and draw out the implications of this for education and for criminal punishment. They bring together a range of issues in contemporary philosophy, including the nature of agency, the modelling of behavioural cognition, ethical implications of personal necessity, moral responsibility for implicit bias, the prospects for character education, and the nature of rightful criminal punishment. The essays emphasise that character is inherently dynamic, challenging the tendency among personality psychologists and virtue ethicists alike to focus on static snapshots of traits, and they emphasise the close integration of character with the individual’s social context, seeking to accommodate the situationist experimental findings within a picture of behaviour as manifesting stable character traits. The volume is intended to demonstrate the deep conceptual affinity of moral philosophy and social psychology and the consequent potential for each to benefit from the other.