"In fact" = "But"?

lewis.waring

Does "In fact" function as a transitional indicator? That is, does in fact signal the switch from context to argument?
eg (PT 64 section III Q 22)
scientists astounding success..........causes public to believe that science can solve any problem. IN FACT, the problems selected by scientists .... etcetc etc

ENTJ

I believe the phrase "in fact" is a term of emphasis within the argument. While "but" functions as the turn in the argument.