Similarly now we have forces at the atomic level that we don't understand how they function, and yet quantum theory is generally accepted as truth.

Please elaborate, because on its face that statement does not seem accurate. We do understand how the electromagnetic, weak, and strong forces function. There are places where quantum field theory fails, but there are plenty of places where it succeeds and makes good predictions.

In contrast, "elan vital" doesn't make any predictions. It doesn't drive curiosity because there's no way to test it and get results that we can then try to understand better.