Yes, that is the title of this thread. As I pointed out in my first post in this thread, the OP has failed to distinguish between the Austrian school of economics and libertarian politics and ethics. Objectivists do not attack Austrian economics as such (as this can be seen in the numerous Austrians that do not hold Mises’ view that there can be no rational ethics or objective values, notably the founder of the Austrian school himself, and the greatest propounder of Mises, Murray Rothbard.) The OP asked “why are we attacked” by Objectivists, confusing “us Austrians” as a genus with “libertarians and anarchists” as a differentia. It is the differentia of “libertarianism,” not the genus “Austrian economics” that Objectivists object to.
If values, including ethical values are subjective, than there cannot be a “rational ethics”.
See Eioul’s post for clarification. Values are subjective in the sense that they depend on a valuer (a “of value to whom”) but values are objective in the sense of what they are used for (a “of value for what”). The “for what” is what the science of ethics deals with. I think you are making the mistake of equating “objective” with “intrinsic.” Objective values are not intrinsic, don’t confuse them. A rational ethics does not posit that there are given obligations or “good and evil” inherent in things apart from any human consciousness. That would be quite literally ir-rational. A rational ethics holds that the good is neither an attribute of “things in themselves” nor of man’s emotional states, but an evaluation of the facts of reality by man’s consciousness according to a rational standard of value.
The objectivity of values originate in a relationship between a man and his survival requirements, that is, they stem from the fact that certain types of action promote human life and are beneficial to human well-being, and certain types of action hinder human life and are detrimental to human well-being. These facts are independent of a particular individual’s tastes or desires or preferences. Praxeology deals with, and indeed correctly states that an observer cannot tell a man what his preferences are better than his own actions, but there is nothing in praxeology that rules out an evaluation of his preferences according to any standard (including an objective standard, such as the biological and psychological requirements for an organism’s survival and flourishing life, or “man’s life qua man” as Aristotle phrased it). It is just the case that praxeology itself cannot fashion such a critique, except to inform a given theory of ethics as to what kind of principles govern human action. Man’s need for a specific code of those principles to promote his life and happiness constitutes his need of morality, i.e. a specific code of values and goals based on the principles of action that will accomplish those ends. Thus, as the fundamental source of moral “oughts” rests in the nature of man, including goal-directed nature of human action, the objective identity of the facts of reality, and the requirements and needs for man’s life and happiness, a scientific ethics is just as possible and necessary (and indeed is implied by) a scientific praxeology. (Indeed praxeology informs us that we cannot escape our need for morality, because we cannot escape from purposeful behavior.)
And by the way, claiming “they exist in separate domains” is not an unsubstantiated claim, that is precisely the claim Ludwig von Mises puts forth in the first chapter of Human Action on the fundamentals of praxeology, and you yourself presumably agree with this, or this is what I can only infer from with your line “is and ought” in the very next bar of your response.