(Argumentum Ad Verecundium, literally "argument from that which is improper"): An appeal to an improper authority, such as a famous person or a source that may not be reliable. This fallacy attempts to capitalize upon feelings of respect or familiarity with a famous individual. It is not fallacious to refer to an admitted authority if the individual's expertise is within a strict field of knowledge. On the other hand, to cite Einstein to settle an argument about education or economics is fallacious. To cite Darwin, an authority on biology, on religious matters is fallacious. To cite Cardinal Spellman on legal problems is fallacious. The worst offenders usually involve movie stars and psychic hotlines. A subcategory is the Appeal to Biased Authority. In this sort of appeal, the authority is one who actually is knowledgeable on the matter, but one who may have professional or personal motivations that render his professional judgment suspect: for instance, "To determine whether fraternities are beneficial to this campus, we interviewed all the frat presidents." Or again, "To find out whether or not sludge-mining really is endangering the Tuskogee salamander's breeding grounds, we interviewed the supervisors of the sludge-mines, who declared there is no problem." Indeed, it is important to get "both viewpoints" on an argument, but basing a substantial part of your argument on a source that has personal, professional, or financial interests at stake may lead to biased arguments.