The most pressing difficulty for deontologist philosophers is justifying constraints.

A deontologist might argue that lying is always wrong, regardless of any potential "good" that might come from lying.

Hence, Kant is a deontologist, in the terminology of contemporary philosophy, particularly that of analytic philosophy.

An important 20th-century deontologist, W.D. Ross, argued for weaker forms of duties called prima facie duties.

Although Hare used many concepts from Kant, especially the idea of universalizability, he was still a consequentialist, rather than a deontologist, in his normative ethical views.

A common contrast between deontology and consequentialist thinking is that the deontologist would argue that "the ends do not justify the means" vs "the ends justify the means".

To attend the medical issues, San Mateo Atenco's community has the following institutions: Centro de Salud C: in San Miguel neighborhood, with one doctor, one deontologist and two nurses.

Tom Regan, who as a deontologist argues that at least some animals are "subjects-of-a-life," with beliefs, desires, memories, and a sense of their own future, who must be treated as ends in themselves, not as a means to an end.