But besides real, there is also apparent truth, or opinion, or prejudice. With regard to real truth, when it is known, the taste which conforms to it is, and must be, uniform. With regard to the second sort of truth, which may be called truth upon sufferance, or truth by courtesy, it is not fixed, but variable. However, whilst these opinions and prejudices, on which it is founded, continue, they operate as truth; and the art, whose office it is to please the mind, as well as instruct it, must direct itself according to opinion, or it will not attain its end. In proportion as these prejudices are known to be generally diffused, or long received, the taste which conforms to them approaches nearer to certainty, and to a sort of resemblance to real science, even where opinions are found to be no better than prejudices. And since they deserve, on account of their duration and extent, to be considered as really true, they become capable of no small degree of stability and determination, by their permanent and uniform nature. As these prejudices become more narrow, more local, more transitory, this secondary taste becomes more and more fantastical; recedes from real science; is less to be approved by reason, and less followed by practice: though in no case perhaps to be wholly neglected, where it does not stand, as it sometimes does, in direct defiance of the most respectable opinions received amongst mankind. Having laid down these positions, I shall proceed with less method, because less will serve to explain and apply them. We will take it for granted, that reason is something invariable, and fixed in the nature of things; and without endeavouring to go back to an account of first principles, which for ever will elude our search, we will conclude that whatever goes under the name of taste, which we can fairly bring under the dominion of reason, must be considered as equally exempt from change. If, therefore, in the course of this inquiry, we can show that there are rules for the conduct of the artist which are fixed and invariable, it follows, of course, that the art of the connoisseur, or, in other words, taste, has likewise invariable principles. Of the judgment which we make on the works of art, and the preference that we give to one class of art over another, if a reason be demanded, the question is perhaps evaded by answering, I judge from my taste; but it does not follow that a better answer cannot be given, though, for common gazers, this may be sufficient. Every man is not obliged to investigate the cause of his approbation or dislike.