With oral and written testimony, humans cannot transmit knowledge

Even the most highly respected authorities can turn out to be wrong.Occasionally this happens because a highly respected authority is dishonest and claims to know something that she or he really doesn't know.Sometimes it happens just because they make a mistake.They think they know when they don't know.For example, a number of respected economists did not expect the financial collapse of 2008.They turned out to be wrong.Maybe they were wrong because they were overlooking some important evidence.Maybe they were wrong because they were misinterpreting some of the evidence they had noticed.