Life in its essence we cannot grasp. We understand it only through its effects, and all human judgment is fallible. Careful and wise observation bring us ever nearer to a knowledge of the conditions which are necessary for human well-being; but experience compels us to recognise the constant failure of theory or dogmatism in dealing with any of the infinitely varied phases of life. In medicine, we are forced to recognise the errors in diagnosis committed even by distinguished men, and to suffer grievous disappointment from the failure of remedies supposed to cure the sick. We cannot fail to note the contradictory results of experiments, the same facts differing according to the observer--one fact upsetting another, and one theory driven out by a later one. This uncertainty resulting from experiment, is strikingly exemplified by the battle of experts about the effects of arsenic displayed in a late criminal trial. Or consider the frequent errors of statistics (a branch of knowledge that enters largely into medical science), owing to the imperfect data on which they are often based, important deductions being drawn from them which are logically indisputable, but entirely false, from the unsound premisses on which they rest. Thus, the death-rate of London, though commonly stated at 23 or 24 per 1,000, is really an unknown quantity, on account of the enormous influx of fresh life and the efflux of broken-down lives. Our women students especially need caution as to the blind acceptance of authority. Young women come into such a new and stimulating intellectual atmosphere when entering upon medical study, that they breathe it with keen delight; they are inclined to accept with enthusiasm the brilliant theory or statement which the active intellect of a clever teacher lays before them. They are accustomed to accept the government and instruction of men as final, and it hardly occurs to them to question it. It is not the custom to realize the positive fact, that methods and conclusions formed by one-half of the race only, must necessarily require revision as the other half of humanity rises into conscious responsibility. It is a difficult lesson also, fully to recognise the limitations of the human intellect, which recognition, nevertheless, is necessary before we can grasp this important and positive fact in human experience--viz., that the Moral must guide the Intellectual, or there is no halting-place in the rapid incline to error. The brilliant professor will always exercise an undue influence over the inexperienced student, and particularly over the woman student. I therefore strongly urge the necessity of cherishing a mild scepticism respecting the dicta of so-called medical science, during the period of student life--scepticism not in relation to truth--that noble object which we hope to approach even more nearly--but scepticism in relation to the imperfect or erroneous statement of what is often presented as truth.