Among the various uses of the term internalism in ethics, there are two that are central and importantly different. In the following entry, these two uses will be distinguished as judgment internalism and reason internalism.

Judgment Internalism

Judgment internalism is the view that moral judgments can be sufficient to motivate actions. Motivation is internal to morality. Externalists, by contrast, hold that the motivation to act morally is supplied by motives that are only contingently related to moral judgments. Internalism is thus opposed to the view that we need to appeal to special motives in order to explain compliance with moral demands, such as sympathy, as well as to a Hobbesian outlook claiming that the motivation to act is always self-interested, and that the motivation to act morally must therefore be self-interested, too. Internalism in this sense has been defended by...