'The merit of what you are pleased to call my philosophy lies, I think, chiefly in having called in question the common theory of ideas, or images of things in the mind, being the only objects of thought—a theory founded on natural prejudices, and so universally received as to be interwoven with the structure of language. Yet, were I to give you a detail of what led me to call in question this theory, after I had long held it as self-evident and unquestionable, you would think, as I do, that there was much of chance in the matter. The discovery was the birth of time, not of genius; and Berkeley and Hume did more to bring it to light than the man that hit upon it. I think there is hardly anything that can be called mine in the philosophy of mind which does not follow with ease from the detection of this prejudice.'
Yet Reid’s Inquiry has been condemned as an unphilosophical appeal from the thoughtful to vulgar intelligence, making the unreflecting many supreme judges in questions intelligible only to the reflecting few. His employment of 'common sense' to express the regulative principle of his philosophy would put his book outside philosophical literature, if this term were taken as a synonym for unreasoned opinion—the average judgments of the man in the street. Reid's own account of what he means by common sense, not to speak of Hume's recognition of the 'deeply philosophical' character of the argument in the Inquiry, should protect him against this imputation. He describes the common sense to which he constantly appeals as 'the first degree of reason,' and as having for its office 'to judge of things self-evident.' As such, he contrasts it with reasoning, or 'the second degree of reason, which draws conclusions that are not self-evident from the self-evident judgments of the common sense.' This distinction between the common rational sense, on which a knowledge of the universe, like the
