Born in Madrid in 1940, the son of the jurist Alfonso García Valdecasas and María Andrada Vanderwilde, José Guillermo received his elementary education at the Colegio los Rosales in Madrid. After obtaining his law degree from the Universidad Complutense, he was awarded a scholarship from the Real Colegio de España in Bologna (Italy) in 1963 through a nationwide contest. He spent two academic years there and earned his PhD in law for the thesis entitled "Sul contratto, idea-mito e strumento tecnico", supervised by Felice Battaglia, for which he won the Luigi Ravà prize. He was appointed rector of the institution in 1978 and continues to hold this post today.
La historia de La Celestina se caracteriza por un constante proceso de ampliación más propio de un libro manuscrito que de un libro impreso. Sabemos, gracias a su propio autor Fernando de Rojas, que la comedia circulaba en forma manuscrita antes de su entrega al impresor y que el mismo introdujo cambios bastante significativos en la version primera. Este ensayo de Jose Guillermo Garcia Valdecasas supone un notable esfuerzo por intentar reconstruir justamente ese texto arquetipo, tal como pudo llegar a manos de su primer impresor. El resultado es un apasionante trabajo de investigacion y una Celestina de un texto corto, libre de postizos, del que surge la asombrosa hermosura del original.