No kind of sport, no kind of game or diversion, has ever given me such enjoyment as lecturing.  Only at lectures have I been able to abandon myself entirely to passion, and have understood that inspiration is not an invention of the poets, but exists in real life, and I imagine Hercules after the most piquant of his exploits felt just such voluptuous exhaustion as I experience after every lecture.

That was in old times.  Now at lectures I feel nothing but torture.  Before half an hour is over I am conscious of an overwhelming weakness in my legs and my shoulders.  I sit down in my chair, but I am not accustomed to lecture sitting down; a minute later I get up and go on standing, then sit down again.  There is a dryness in my mouth, my voice grows husky, my head begins to go round....  To conceal my condition from my audience I continually drink water, cough, often blow my nose as though I were hindered by a cold, make puns inappropriately, and in the end break off earlier than I ought to.  But above all I am ashamed.

My conscience and my intelligence tell me that the very best thing I could do now would be to deliver a farewell lecture to the boys, to say my last word to them, to bless them, and give up my post to a man younger and stronger than me.  But, God, be my judge, I have not manly courage enough to act according to my conscience.

Unfortunately, I am not a philosopher and not a theologian.  I know perfectly well that I cannot live more than another six months; it might be supposed that I ought now to be chiefly concerned with the question of the shadowy life beyond the grave, and the visions that will visit my slumbers in the tomb.  But for some reason my soul refuses to recognize these questions, though my mind is fully alive to their importance.  Just as twenty, thirty years ago, so now, on the threshold of death, I am interested in nothing but science.  As I yield up my last breath I shall still believe that science is the most important, the most splendid, the most essential thing in the life of man; that it always has been and will be the highest manifestation of love, and that only by means of it will man conquer himself and nature.  This faith is perhaps naive and may rest on false assumptions, but it is not my fault that I believe that and nothing else; I cannot overcome in myself this belief.

But that is not the point.  I only ask people to be indulgent to my weakness, and to realize that to tear from the lecture-theatre and his pupils a man who is more interested in the history of the development of the bone medulla than in the final object of creation would be equivalent to taking him and nailing him up in his coffin without waiting for him to be dead.