in general, whatever is subservient to a cause in producing any effect.

Instrument is also used in law to signify some public act, or authentic deed, by means of which any truth is made apparent, or any right or title established, in a court of justice.

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1 Essay on Man. 2 Zoonomia, vol. i. p. 139, third edition corrected, 1801. 3 Were this very arbitrary limitation of the word Instinct adopted, we should be forced to reject as improper, the employment of that term in the passage formerly quoted from Mr Smith, in which he speaks of the instinctive perception of distance from the eye in certain classes of animals. The same use of the word occurs in various other parts of his works. "There seems," he observes on one occasion, "to be in young children an instinctive disposition to believe whatever they are told." And a few pages afterwards, "The desire of being believed, the desire of persuading, leading, and directing other people, seems to be the strongest of all our natural desires. It is perhaps the instinct upon which is founded the faculty of speech, the characteristical faculty of human nature." (Theory of Moral Sentiments, vol. ii. pp. 352, 354, sixth edition.) As an authority for the usual acceptation of a philosophical term, Mr Smith will be allowed to rank somewhat higher than Dr Darwin.