There are several major proponents of deontological ethics, including Immanuel Kant and W.D. Ross.

Immanuel Kant is considered one of the most influential philosophers in the deontological tradition. According to Kant, ethical decisions should be based on universal moral principles, which he referred to as the “categorical imperative.” The categorical imperative is a rule that applies to everyone, regardless of their particular circumstances or desires. For example, Kant believed that it is always unethical to lie, regardless of the consequences of telling the truth.

Kant argued that ethical decisions should be based on reason and rationality, rather than emotion or personal preference. He believed that ethical principles are objective and universal, and that they can be discovered through the use of reason.

W.D. Ross was another influential proponent of deontological ethics. Ross believed that ethical decisions should be based on a set of prima facie duties, or moral obligations that are self-evident and intuitive. These duties include things like the duty to tell the truth, the duty to keep promises, and the duty to avoid harming others.

According to Ross, these duties can sometimes conflict with each other, and it is up to the individual to determine which duty is more important in a given situation. For example, the duty to tell the truth might conflict with the duty to avoid causing harm, and it is up to the individual to determine which duty takes precedence.

Both Kant and Ross believed that deontological ethics provides a clear and objective framework for making ethical decisions, based on universal moral principles and intuitive duties. They believed that this approach to ethics is superior to other approaches that focus on the consequences of actions or the development of virtuous character traits.