Shortly after this unpleasant event, Nietzsche, urged by his sister, made a half-hearted attempt to secure a professorship at the University of Leipzig, but negotiations for the post fell through, due largely to Nietzsche's own indifference in the matter. Soon after this the philosopher became estranged from his sister because of her intention to marry Dr. Förster. Nietzsche's opposition to the marriage--an opposition which was supported by his mother--was due to several reasons. First, it would necessitate his sister leaving him and accompanying her husband to Paraguay. Secondly, it had been rumoured that Dr. Förster had severely criticised his books. And thirdly, Nietzsche had small respect for Dr. Förster himself, who was an impractical idealist and an anti-Semite. However, despite all the family protestations, the marriage took place. Nietzsche was disappointed and brooded over the event, but a year later he became reconciled with his sister, and she remained, to the end of his life, his closest friend and companion. In January, 1889, an apoplectic fit, which rendered Nietzsche unconscious for two days, marked the beginning of the end. His manner suddenly became alarming. He exhibited numerous eccentricities, so grave as to mean but one thing: his mind was seriously affected. There has long been a theory extant that his insanity was of gradual growth. Nordau holds that he was unbalanced from birth. But there is no evidence to substantiate these two theories. For seven years Nietzsche's physical condition had been improving, and his mind up to the end of 1888 was perfectly clear and gave no indication of what his end would be. During this period his books were thought out in his most clarified manner; in all his intercourse with his friends he was restrained and normal; and his voluminous correspondence showed no change either in sentiment or in tone. The theory advanced in some quarters that his books, and especially his later ones, were the work of a madman, is entirely without foundation. His insanity was sudden; it came without warning; and it is puerile to point to his state of mind during the last years of his life as a criticism of his work. His books must stand or fall on internal evidence--and on nothing else. Judged from that standpoint they are scrupulously sane.