To urge the necessity of learning practical fitting as a part of an engineering education is superfluous. A mechanical engineer who has not been "through the shop" can never expect to attain success, nor command the respect even of the most inferior workmen; without a power of influencing and controlling others, he is neither fitted to direct construction, nor to manage details of any kind connected with engineering industry. There is nothing that more provokes a feeling of resentment in the mind of a skilled man than to meet with those who have attempted to qualify themselves in the theoretical and commercial details of engineering work, and then assume to direct labour which they do not understand; nor is a skilled man long in detecting an engineer of this class; a dozen words in conversation upon any mechanical subject is generally enough to furnish a clue to the amount of practical knowledge possessed by the speaker.194With Socrates and Plato, scepticism exhibits itself under two new aspects: as an accompaniment of religious belief, and as an element of constructive thought. Thus they represent both the good and the bad side of this tendency: the aspect under which it is a help, and the aspect under which it is a hindrance to scientific investigation. With both philosophers, however, the restriction or negation of human knowledge was a consequence rather than a cause of their theological convictions; nor do they seem to have appreciated its value as a weapon in the controversy with religious unbelief. When Socrates represented the irreconcilable divergence in the explanations of Nature offered by previous thinkers as a sufficient condemnation of their several pretensions, he did not set this fact against the arguments by which a Xenophanes had similarly endeavoured to overthrow the popular mythology; but he looked on it as a fatal consequence of their insane presumption in meddling with the secrets of the gods. On one occasion only, when explaining to Euthydmus that the invisibility of the gods is no reason for doubting their existence, he argues, somewhat in Butlers style, that our own minds, whose existence we cannot doubt, are equally invisible.222 And the Platonic Socrates makes it134 his business to demonstrate the universality of human ignorance, not as a caution against dogmatic unbelief, but as a glorification of the divine knowledge; though how we come to know that there is any such knowledge he leaves utterly unexplained."It was part of a plot to ruin us both," Bruce said moodily. "I should have been charged with criminal carelessness, which is fatal to a doctor, and you would have been guilty of administering an overdose. That woman, we know who she was, changed the bottles once and would have changed them again, in fact that is why she returned--the Countess."