Comparison of Kant and Mill

Similarities

The following similarities were noted by Dr. Hitchcock:

Both propose to base morality on a single first principle (for Kant the categorical imperative in its three supposedly equivalent formulations, for Mill the principle of utility).

Both incorporate in their proposed first principle of morality a kind of universality, in Kant's case that of restricting one's rules of action to those that one can will to be a universal law of nature, in Mill's case considering the consequences of a kind of action for all humans and sentient creatures.

Both recognize intermediate moral rules, called by Kant "duties" and by Mill "subordinate principles".

Thus both have a two-stage conception of moral thinking, a "critical stage" in which one tests proposed intermediate moral rules against the first principle of morality and an "application stage" in which one makes a decision in a particular case on the basis of the relevant moral rules.

The duties to others recognized by Kant correspond to the subordinate principles recognized by Mill: not to lie, to be beneficent, not to steal, not to deprive others of liberty.

Both postulate a responsibility to contribute to the happiness of all other human beings, Kant in taking treating humanity as an end in itself to mean contributing positively to the ends of other persons (cf. his 4th example) and in taking legislation for a realm of ends as making everyone else's ends one's own (combined with his claim that every human being by nature desires their own happiness) and Mill directly in his principle of utility.

Both appeal to consequences in the application of their first principle to the derivation of duties, Kant in considering the consequences of a maxim's becoming a universal law of nature and Mill in considering the consequences of a certain kind of action (e.g. lying).

The following similarities were noted by members of the class:

Both appeal to rationality to evaluate morality, in the sense that they reason from a fundamental principle about what is morally right or wrong.

Both recognize the existing of a "moral sense", although neither regards it as the basis of morality (unlike the 18th century Scottish moral sense theorists).

Both extend the scope of moral agency (who has moral responsibilities) to all rational beings (although Mill does not explicitly refer to any beings other than humans as moral agents).

Differences

Differences noted by Dr. Hitchcock
Respect Kant Mill
method of justifying the first principle appeal to reason legislating a law for itself (reason) appeal to what people desire as an end (experience)
status of morality self-imposed legislation of the will of a rational being instrument of social control of individual behaviour
basic motivation for conforming to morality respect for one's own autonomy desire to be in harmony with one's fellow human beings
attitude to popular morality agreement willingness to reform
allowance for exceptions to intermediate moral rules minimal where social utility (all things considered) indicates
scope of morality rational beings sentient creatures
focus in the derivation of the principle of morality moral worth of the action (i.e. the agent) moral correctness of the action
source of moral rightness or wrongness of an action its maxim (the agent's subjective rule of conduct) the consequences of that type of action
duties to oneself recognized (no suicide, develop one's talents) none (see "On Liberty")


Differences noted by students in the class (some overlap with above table, wording has been changed to improve accuracy and clarity)
Respect Kant Mill
basis of morality exclusively rational not exclusively rational
starting point for evaluation moral worth of action (focus on agent) type of action and consequences
focus of evaluation individual agent collective consequences
touchstone of morality objective standard (duties tend to be exceptionless) what will produce more happiness (subordinate principles have exceptions)
motivation for acting morally internal respect for one's own autonomy (self-legislation) external as well as internal sanctions (ultimately, desire for harmony of our interests with those of others)
epistemic status of morality innate acquired and cultivated
conception of the good the good will (end is happiness plus deserving happiness) happiness (pleasure and the absence of pain)
scope of morality (those protected by it) rational beings (and perhaps sentient creatures indirectly) sentient creatures
attitude to conflicting duties indeterminate resolvable by principle of utility
social context needed for morality? no yes