There is nothing indeed of which the physician is more aware than of the power of the mind in assisting or reading convalescence." The instances here mentioned are chiefly instances of the effects of mental stimulants on the bodily frame.

No person has ever for a moment doubted the near, though mysterious, connection of mind and body.

But it is arguing totally without knowledge of the nature of stimulants to suppose, either that they can be applied continually with equal strength, or if they could be so applied, for a time, that they would not exhaust and wear out the subject.

In some of the cases here noticed, the strength of the stimulus depends upon its novelty and unexpectedness.

Such a stimulus cannot, from its nature, be repeated often with the same effect, as it would by repetition lose that property which gives it its strength.
In the other cases, the argument is from a small and partial effect, to a great and general effect, which will in numberless instances be found to be a very fallacious mode of reasoning.