I'm a Rand Paul guy, but Sanders makes some valid points. America is very greedy and violent. What we don't have here, we'll go around the world and take it from someone else. We practice the 'Might makes Right' philosophy.
We're a very materialistic people. And that quest for the almighty dollar, makes us insane. We often rationalize treating others badly, by falling back on 'It's about the profit.' We can't treat people as well if it means making less profit. It's a tough dilemma. It's the pitfall of being only about money. It's all in the Bible. Greed kills. We're human.
To your point:
"...The turn introduced by the Renaissance was probably inevitable historically: the Middle Ages had come to a natural end by exhaustion, having become an intolerable despotic repression of man's physical nature in favor of the spiritual one. But then we recoiled from the spirit and embraced all that is material, excessively and incommensurately. The humanistic way of thinking, which had proclaimed itself our guide, did not admit the existence of intrinsic evil in man, nor did it see any task higher than the attainment of happiness on earth. It started modern Western civilization on the dangerous trend of worshiping man and his material needs.
Everything beyond physical well-being and the accumulation of material goods, all other human requirements and characteristics of a subtle and higher nature, were left outside the area of attention of state and social systems, as if human life did not have any higher meaning. Thus gaps were left open for evil, and its drafts blow freely today. Mere freedom per se does not in the least solve all the problems of human life and even adds a number of new ones.
And yet in early democracies, as in American democracy at the time of its birth, all individual human rights were granted on the ground that man is God's creature. That is, freedom was given to the individual conditionally, in the assumption of his constant religious responsibility. Such was the heritage of the preceding one thousand years. Two hundred or even fifty years ago, it would have seemed quite impossible, in America, that an individual be granted boundless freedom with no purpose, simply for the satisfaction of his whims.
Subsequently, however, all such limitations were eroded everywhere in the West; a total emancipation occurred from the moral heritage of Christian centuries with their great reserves of mercy and sacrifice. State systems were becoming ever more materialistic. The West has finally achieved the rights of man, and even excess, but man's sense of responsibility to God and society has grown dimmer and dimmer. In the past decades, the legalistic selfishness of the Western approach to the world has reached its peak and the world has found itself in a harsh spiritual crisis and a political impasse. All the celebrated technological achievements of progress, including the conquest of outer space, do not redeem the twentieth century's moral poverty, which no one could have imagined even as late as the nineteenth century.
As humanism in its development was becoming more and more materialistic, it also increasingly allowed concepts to be used first by socialism and then by communism, so that Karl Marx was able to say, in 1844, that "communism is naturalized humanism."
This statement has proved to be not entirely unreasonable. One does not see the same stones in the foundations of an eroded humanism and of any type of socialism: boundless materialism; freedom from religion and religious responsibility (which under Communist regimes attains the stage of antireligious dictatorship); concentration on social structures with an allegedly scientific approach. (This last is typical of both the Age of Enlightenment and of Marxism.) It is no accident that all of communism's rhetorical vows revolve around Man (with a capital M) and his earthly happiness. At first glance it seems an ugly parallel: common traits in the thinking and way of life of today's West and today's East? But such is the logic of materialistic development.
The interrelationship is such, moreover, that the current of materialism which is farthest to the left, and is hence the most consistent, always proves to be stronger, more attractive, and victorious. Humanism which has lost its Christian heritage cannot prevail in this competition. Thus during the past centuries and especially in recent decades, as the process became more acute, the alignment of forces was as follows: Liberalism was inevitably pushed aside by radicalism, radicalism had to surrender to socialism, and socialism could not stand up to communism...." Alexander Solzhenitsyn - Harvard Address, 1978