deficiencies are cunningly concealed, while the false conclusions are admired as sublime wisdom. In other cases, partial experiences are accumulated to found a hypothesis, and all contradictory phenomena are either ignored, or the meaning of words is changed according to the requirements of the reasoning. Nor is it only the philosophical quack who employs these conjuring tricks to deceive the public; without being conscious of it, the most upright and the least prejudiced thinker uses analogous means to satisfy his thirst for knowledge directly that he issues from the only sphere where reason can legitimately enjoy the fruit of its activity. After what you have heard me say on former occasions, Julius, these expressions must cause you no little astonishment; yet they are not the product of a sceptical caprice. I could lay before you the foundations on which they rest, but this would require, as prelude, a somewhat dry examination into the nature of human knowledge,--and I prefer to reserve this for a time when you will feel the want of it. You have not yet arrived at that state of mind when humiliating truths on the limits of human knowledge can have any interest for you. Make a first essay with the system which has supplanted your own in your mind. Examine it with the same impartiality as severity. Proceed in the same manner with other theories with which you have recently become acquainted; and if none of them can fully satisfy your requirements, you will ask yourself if, after all, these requirements are reasonable. Perhaps you will tell me this is a poor consolation. You will infer that resignation is your only refuge after so many brilliant hopes had been raised. "Was it worth while," you will say, "to challenge me to a full exercise of my reason in order to set bounds to it at the very moment when it was beginning to bear the noblest fruit? Was I only to become acquainted with a higher enjoyment in order to feel with a double keenness how painful it is to be thus bounded?"