Claim: The best test of an argument is its ability to convince someone with an opposing viewpoint.Reason: Only by being forced to defend an idea against the doubts and contrasting views of others does one really discover the value of that idea.

Is the best test of an argument its capability to persuade people with a contrasting view point? The speaker claims so, for only after a person defends an idea against opposing point of view, will the person really understand the value of that viewpoint. In my opinion, defending the idea does not render anything meaningful to discovery of the value of that idea when there is an undue discord in opinions. Otherwise, I concede that defending an idea against dichotomous perspective contributes to realization of the importance of that idea under a particular circumstance.

First of all, under some circumstances debate against contrasting point of view does not provide basis for realizing the value of a viewpoint. For example, realization of value of an idea is unlikely in an acrimonious discourse or debate, during which opponents vie for their voices heard, but have little interest in finding the common ground and in acknowledging the merits of the opponent’s viewpoint. In this case, neither party realizes much about the value of their viewpoint. Rather, the argument only serves to reinforce the predispositions and biases, which render nothing meaningful for the discovery of their idea’s value.

Moreover, realization of significance of a perspective will also be unlikely when fundamental assumptions on which the combatants’ beliefs are entrenched are dichotomous. For example, theology students may preclude any possibility of an idea associated with evolutionary process because such idea may be contradictory to imperative assumptions in theology. This contradiction in assumptions would impede neither theology students nor evolutionary biology students to learn about the value of each other’s ideas, for two assumptions cannot simultaneously be correct. Unless the undue discord in assumption is somehow resolved, it is unlikely that any debate will yield realization of a particular idea’s worth.

Otherwise, that value of an idea can truly be understood when the idea is defended against opposing ones is cogent. For supporting example one can consider a debate between an economist and a political scientist on the best economic policy in a country. By debating, the economist will realize that their laissez-fair economic policy primarily assumes utilitarianism under which people optimize welfare by maximizing the total wealth within an economy. Moreover, they will realize maintaining political stability requires much more consideration than such utilitarianistic perspective. On the other hand, the political scientist may realize populist political stance can severely impair potential long-run economic growth by hampering the economy’s productive capacity. This example shows that debate between two parties, who are willing to listen to the ideas of opponent and to acknowledge the merits of opposing idea, would contribute to realization of not only what has been neglected and therefore needs to be addressed, but also what aspect of the idea provides discriminating insights to others—that is, the realization of an idea’s worth.

To sum up, there is some truths in the speaker's claim, but defending an argument against the contrasting views of others is not sufficient for the discovery of the idea's value. Unless parties involved in an argument are not prepared to objectively assess the validity of the perspective, there is a potential for the parties to mutually understand their idea’s shortcoming and worth.