In America the basic argument between the Right and the Marxists is from tractate Ketuboth page 9. That is do you go by חזקת השתא או חזקה מעיקרא the state of things now or the state of things before. That is do you assume conditions now always existed until you reach the point where you know they did not. I.e. prosperity, freedom, etc all the markers of Western Civilization. Until you reach the point of despair and poverty when you know these conditions did not apply.  

Or do you assume the state of mankind was poor and desperate short and brutal until something like the USA came along to make it different. [Even the age of Mozart does not count since it was only capitalism that made conditions of prosperity and freedom apply to everyone, not just the monarch.] 

Well clearly the Gemara holds that we go by the state of things before and you push that forwards as far as possible until something you know changed it. That is the Constitution of the USA.

Certainly Marxism did not make things prosperous or make people free in any country that has ever tried it. The long lines in Russia just to get a few groceries shows that.

So we know it was capitalism that changed the original conditions of mankind.

[The basic issue in Ketuboth is that a priest marries and then comes to court and says he found his new bride not to be a virgin. [i.e. no hymen]. So she is forbidden to him. But if a Israeli comes and says the same thing she is permitted to him because it is a ספק ספקא doubt of a doubt. Maybe she had sexual relations before Kidushin. Then she is permitted. But even if she had relations after Kidushin, it might have been against her will. So she is still permitted. 

Tosphot asks why not go by חזקת כשרות that every person starts out with. That is--they are Ok util you know otherwise. Tosphot answers because of חזקה מעיקרא the original state of things. That is..you assume she was a virgin until the very second you found out otherwise. That means after the Kidushin and so she is forbidden to the Koken,

So we see we go by the original state of things even when there is a present state of things against it.

[That is from Rav Akiva Eigger and Rav Shach.]