"So much is new and complex today that looking back for an understanding of the past provides little guidance for living in the present."
The speaker claims that since so much in today's world is new and complex the past provides little guidance for living in the present. I agree with this assertion insofar as history offers few foolproof panaceas for living today. However, I disagree with the speaker's claim that today's world is so unique that the past is irrelevant. One good example that supports my dual position is the way society has dealt with its pressing social problems over time.
Admittedly, history has helped us learn the appropriateness of addressing certain social issues, particularly moral ones, on a societal level. Attempts to legislate morality invariably fail, as illustrated by Prohibition in the 1930s and, more recently, failed federal legislation to regulate access to adult material via the Internet. We are slowly learning this lesson, as the recent trend toward legalization of marijuana for medicinal purposes and the recognition of equal rights for same-sex partners both demonstrate.
However, the only firm lesson from history about social ills is that they are here to stay. Crime and violence, for example, have troubled almost every society. All manner of reform, prevention, and punishment have been tried. Today, the trend appears to be away from reform toward a "tough-on-crime" approach. Is this because history makes clear that punishment is the most effective means of eliminating crime? No; rather, the trend merely reflects our current mores, attitudes, and political climate.
Another example involves how we deal with the mentally-iii segment of the population. History reveals that neither quarantine, treatment, nor accommodation solves the problem, only that each approach comes with its own trade-offs. Also undermining the assertion that history helps us to solve social problems is the fact that, despite the civil-fights efforts of Martin Luther King and his progenies, the cultural gap today between African-Americans and white Americans seems to be widening. It seems that racial prejudice is a timeless phenomenon.
To sum up, in terms of how to live together as a society I agree that studying the past is of some value; for example, it helps us appreciate the futility of legislating morality. However, history's primary sociological lesson seems to be that today's social problems are as old as society itself, and that there are no panaceas or prescriptions for solving these problems---only alternate ways of coping with them.