The True, like the Good, is often hard to capture but always worth pursuing. That in itself poses difficulties.
The liberal arts attempts to separate (though never alienate) the True from the true. Many truths are observable, like scientific facts. The Earth is round, things fall when we drop them, and light has characteristics of both particles and waves. These descriptions of the natural world do not depend on our awareness of them to be accurate, nor do they change with our knowledge. For instance, the ancient belief that the world is flat does not mean that it was flat when they made their observations. Natural truths are not relative, even when knowledge is situational.
Capital-T Truths are more complicated because they rely on the difference between what is and what should be, lest they fall into the naturalist's fallacy. There are factual descriptions of how the world is AND factual descriptions of how the the world should be. It is equally true that man is not always kind and that man should be kind; it is equally true that society often falls short of justice and that society ought to be just.
The Truth deals with, as Alan Bloom poses it in The Closing of the American Mind, "'What is man?', in relation to his highest aspirations as opposed to his low and common needs."*
Thus, as Allan Bloom writes, one of the dangers is claiming that, because everyone has a different understanding of Truth, Truth does not exist. The result is relativism:
Openness—and the relativism that makes it the only plausible stance in the face of various claims of truth and various ways of life and kinds of human beings—is the great insight of our times. The true believer is the real danger. The study of history and culture teaches that all the world was mad in the past; men always thought they were right, and that led to wars, persecutions, slavery, xenophobia, racism and chauvinism. The point is not to correct the mistakes and really be right; rather it is not to think you are right at all.**
The other way to reject Truth (which is opposed to relativism in theory, but identical in practice) is nihilism. Instead of saying everything is true because it seems true to someone, nihilism says that because everything is true to someone, nothing is True. Both use personal preferences and beliefs as standards for living.
The liberal arts do not pretend to know what Truth is, but rather aim to discover it. They say that Truth exists, even if it is difficult to define or discover. The student trained in the liberal arts is able to evaluate themselves and the world around them, assessing their relation to Truth. For instance, they can assess different governments based on what they believe man is and should be. Thus, they can be better equipped to assess themselves, as well.
*Allan Bloom, The Closing of the American Mind: How Higher Education Has Failed Democracy and Impoverished the Souls of Today's Students (New York: Simon and Schuster, 1987), 21.