For a North American seeking to know the Mexican mind, and especially the sciences today and in their recent development, a great light of genius is to be found in Mexico City in the late 17th century. Tbe genius is that of one who surely may be counted as the first Mexican philosopher of nature, a nun of the Order of Saint Jerome: Sor Juana Ines de la Cruz. Sor Juana must speak for herself, from her penetrating exercise of an independent mind within a political and religious formation which denigrated women and circumscribed reason itself. To understand this world of ours, to join in an