Form and content are common metaphysical terms in philosophy. The form is the “shape” of the thing, a container without content. Concepts of “good” and “right” are forms. The content is the specific manifestation of that form. Something “good” might refer to helping someone in need. This is the content. Therefore, ethical formalism rejects the concern with actual moral acts and concentrates instead on the fundamental sources of moral goodness regardless of their application.
Any ethical theory has a form, or rule of action, and content, the specific nature of that action. Ethical formalism dispenses with content altogether. Formalism is ethical universalism made into laws that are absolute. Therefore, the content of any specific moral action has no meaning. If a universal law says “do not cheat,” then under no circumstances is cheating permissible.
Immanuel Kant is one of the more important promoters of ethical formalism. In his view, no ethical theory can worry about the actual content of specific moral acts – it must make rules based exclusively on the constitution of the human will itself. This suggests that the human will can apply rules to every and all situations that confront it. It begins from the point of view of human equality and resolves itself to the idea that only universal laws decided upon in freedom can contain anything moral.
Ethical formalism holds that the source and ground of ethical laws contains their value. Therefore, consequences do not matter. Kant's famous formalist principle is one of the most famous of ethical formalist ideas. For Kant, a truly moral action is one that comes from the free will. The will is free when no outside influences, such as self-interest, interfere with it. The will in this case is totally free, and therefore totally universal.
Ethical action deriving from the will is truly good because it is both free and universal. Universality becomes the ground of morality because it does not take into consideration any specific interest. It is moral for the sake of being moral.
Kant's famed ethical formalism shows the source of moral action through a will that is totally free from constraint, and hence, necessarily totally universal. All rational human beings are capable of this sort of action. Since this is the source of moral goodness, and all human beings can perform it, then each rational person is the source of moral good. If this is true, then all human beings must be treated as ends in themselves, never as means. The very concept of universality means that real moral rules must apply to everyone equally.