What is ethical subjectivism?
A.J. Ayer (1910–1989) put forth this view in Language, Truth and Logic (1936). A more comprehensive account was given by Charles L. Stevenson (1908–1979) in Ethics and Language (1944). Stevenson argued that moral judgments do not have cognitive meaning, but rather emotive meaning. He meant that moral judgments are not factual in nature, but are rather emotional reactions to facts, which are sometimes meant to influence others. If the facts or other circumstances changed, so could the moral judgment.
Ethical subjectivism is either the same as ethical emotivism, or the view that ethical judgments express our shared emotions, or else it refers to an individual’s private moral views as the meaning of morality, so that in principle there could be as many moral systems as there are individuals.