We are free in so far as our freedom “consists with every other person’s freedom,” or “so long as we do not attempt to deprive others of theirs or impede their efforts to obtain it.” In other words, “each person has the same indefeasible claim to a fully adequate scheme of equal basic liberties, which scheme is compatible with the same scheme of liberties for all.”

     Theses famous principles by well-known moral and political philosophers like Immanuel Kant, John Stuart Mill, and John Rawls seem very clear and reasonable prima facie. However, these principles, especially terms like “in so far as,” “so long as,” “consist with,” and “compatible with” in them, are so ambiguous, vague, and broad that even fanatic persons and tyrannies can misuse them to justify their brutal violent actions.

     I try to show that to clarify these principles and terms and to establish a free tolerant society and reasonable conceptions of liberty, we need a morally relevant epistemological distinction on harms. I call it the objective/subjective distinction. To harm somebody, that is to act against her interests, per se cannot be morally impermissible. It means that there are harmful actions that can still be “compatible with the scheme of basic liberties for all,” and “consist with every other person’s freedom.” I call these harms “subjective,” and I think giving the agent the right to do them is a pre-condition of any free tolerant society.

     I propose two criteria to recognize a harm as subjective: 1. the person will not be harmed if she changes some of her personal beliefs or, at least, will give the agent the right to do it; or 2. we can imagine some people exactly in the same situation who are not harmed by the same action or, at least, give the agent the right to do it. Wearing clothes that harm some person(s), delivering a lecture which some person(s) may find annoying, speaking about an idea which some person(s) may find disgusting or repugnant, are all good examples of subjective harms.