What is the original sin argument?

The progress and happiness of society in the world in all ages have been impeded and marred by bad men―monsters I would say from the unprincipled politicians in our midst to kings, emperors and popes. I desire to know if those frauds on mankind still hold their influence in the spiritual world?

 

To a certain extent they do. 

You should consider that all that this life has produced―all that belongs to it, either natural or spiritual, is in the imperfect state consequent on the imperfect state of the earth. 

It has not yet arrived at that point of perfection by which it can sustain good men or women entire. 

There are poisonous plants everywhere on the surface of the earth and there are poisonous theories everywhere. There is spiritual poison as there is material poison, and both I believe are legitimate children of this planet, the earth. Now then as the earth grows, becomes more perfect, more spiritually unfolded and more naturally unfolded, it will give you a higher type, not only in the vegetable, mineral and animal, but in the spiritual. 

But all these things come by slow degrees. 

The world was not made in six days by any means. Man was not created in the twinkling of an eye, but thousands on thousands, millions on millions of years rolled away before thought was born. 

Now you have just as good a class of men and women on the earth as the earth can take care of. 

Be satisfied―work on as the earth works on. The earth does not complain. It performs its mission and you will perform yours whether you desire to or not.

―Theodore Parker in Spirit