by evidence, or drawn out into demonstrations; they are therefore wholly subject to the imagination, and do not force their effects upon a mind preoccupied by unfavourable sentiments, nor overcome the counter-action of a false principle or of stubborn partiality.
To convince any man against his will is hard, but to please him against his will is justly pronounced by Dryden to be above the reach of human abilities. Interest and passion will hold out long against the closest siege of diagrams and syllogisms, but they are absolutely impregnable to imagery and sentiment; and will for ever bid defiance to the most powerful strains of Virgil or Homer, though they may give way in time to the batteries of Euclid or Archimedes.
In trusting therefore to the sentence of a critick, we are in danger not only from that vanity which exalts writers too often to the dignity of teaching what they are yet to learn, from that negligence which sometimes steals upon the most vigilant caution, and that fallibility to which the condition of nature has subjected every human understanding; but from a thousand extrinsick and accidental causes, from every thing which can excite kindness or malevolence, veneration or contempt.
Many of those who have determined with great boldness, upon the various degrees of literary merit, may be justly suspected of having passed sentence, as Seneca remarks of Claudius,
Sæpe et nulla,
without much knowledge of the cause before them: for it will not easily be imagined of Langbane, Bor-
