"One day he (Einstein) said that the only mechanical force more powerful than steam, electricity and atomic energy is will," Mourinho told a news conference on the eve of the first leg of the semi-final between the two great rivals.
"That Alberto bloke was not stupid. With will you can achieve things."
Mourinho led Inter Milan to victory in last year's edition of Europe's elite club competition after disposing of Pep Guardiola's Barca side in the semis.
The Portuguese coach, having taken over at Real Madrid this season, saw his new team overcome favourites Barcelona to win the King's Cup final in Valencia last week.
However, Mourinho reminded reporters on Tuesday that he was still the same coach who suffered a 5-0 La Liga drubbing at Barca's hands at the Nou Camp in November.
"They (Barca) are a top team with a top coach and everything is possible," he said at Real's training ground on Tuesday.
"I am exactly the same coach who lost 5-0 to Barcelona and I don't have any magic potion."
Whatever Mourinho might say, the balance of power has shifted somewhat since then, with Real fighting back with 10 men to salvage a 1-1 La Liga draw at the Bernabeu this month before beating their arch-rivals 1-0 in the domestic cup final.
"We played a great game in Valencia (in the cup final) but tomorrow is another match. We have to play at our top level and not be influenced by what has already passed," added Mourinho who will be without injured midfielder Sami Khedira.
Mourinho, assistant to Bobby Robson and Louis van Gaal at Barca from 1996 to 2000, said it was difficult to predict which side would progress to the May 28 final at Wembley stadium.
"These are two teams that know each other well, with tradition, with players who know success and what it means to play important games," he said.
"My opinion is that there are no favourites. In a semi-final with two legs there are no favourites."
Real, the nine-times European Cup winners, have beaten Barcelona twice before at the same last-four stage of the competition en route to their triumphs in 1960 and 2002.
Wednesday's match falls exactly 51 years after their 3-1 win at the Nou Camp in the second leg of the 1959/60 European Cup semi-final.
In the first round of the following season's competition, Barca knocked Real out of the European Cup.
