Science and politics: Ramon y Cajal's intervention in Giuseppe Levi's 1934 liberation.

In this article we present and comment on three letters written, respectively, by Fernando de Castro, Santiago Ramon y Cajal, and Justo Gomez Ocerin, concerning the imprisonment and liberation of the Italian scientist Giuseppe Levi in 1934. These documents reveal the great interest that Ramon y Cajal took in the problem and his intervention in the liberation of his colleague. In addition, they show that the controversy about collaterals between Golgi and Cajal was still alive and demonstrate that Cajal did not possess Golgi's original publication.