Nietzsche, The Gay Science:
Multiplication table. —One is always wrong, but with two, truth begins. —One cannot prove his case, but two are irrefutable. (§260)
Ludwig von Mises, Socialism:
Computation demands units. And there can be no unit of the subjective use-value of commodities. Marginal utility provides no unit of value….
In an exchange economy, the objective exchange value of commodities becomes the unit of calculation….We are able to take as the basis of calculation the valuation of all individuals participating in trade. The subjective valuation of one individual is not directly comparable with the subjective valuation of others. It only becomes so as an exchange value arising from the interplay of the subjective valuations of all who take part in buying and selling….Calculations based upon exchange values enable us to reduce values to a common unit. (98-99)
Hannah Arendt, “The Crisis in Culture,” in Between Past and Future:
The power of judgment rests on a potential agreement with others, and the thinking process which is active in judging…finds itself always and primarily…in an anticipated communication with others with whom I know I must finally come to some agreement. From this potential agreement judgment derives its specific validity. This means, on the one hand, that such judgment liberate itself from the “subjective private conditions,” that is, from the idiosyncrasies which naturally determine the outlook of each individual in his privacy and are legitimate as long as they are only privately held opinions, but which are not fit to enter the market place, and lack all validity in the public realm. And this enlarged way of thinking, which as judgment knows how to transcend its own individual limitations, on the other hand, cannot function in strict isolation or solitude; it needs the presence of others “in whose place” it must think, whose perspectives it must take into consideration, and without whom it never has the opportunity to/operate at all….
…Common sense…discloses to us the nature of the world insofar as it is a common world; we owe to it the fact that our strictly private and “subjective” five senses and their sensory data can adjust themselves to a nonsubjective and “objective” world which we have in common and share with others. Judging is one, if not the most, important activity in which this sharing-the-world-with-others comes to pass.
…In aesthetic no less than in political judgments, a decision is made, and although this decision is always determined by a certain subjectivity, by the simple fact that each person occupies a place of his own from which he looks upon and judges the world, it also derives from the fact that the world itself is an objective datum, something common to all its inhabitants. The activity of taste decides how this world, independent of its utility and our vital interests in it, is to look and sound, what men will see and what they will hear in it. (220-222)
Arendt, “Some Questions of Moral Philosophy,” in Responsibility and Judgment:
The validity of common sense grows out of the intercourse with people…The validity of such judgments would be neither objective and universal nor subjective, depending on personal whim, but intersubjective or representative. (141)