opponents and their tenets with a respect and a solemnity that sometimes tempt me to smile. His style is clear and simple; and his aversion to the word idea is so great, that I think he never once uses it in delivering his own opinions. It was not without reason that Stillingfleet took the alarm at Mr. Locke’s indiscreet use of that word. It was indeed an ignis fatuus that decoyed him in spite of his excellent understanding into a thousand pits and quagmires. Berkeley it bewildered still more. And it reduced David Hume to the condition of a certain old gentleman of whom we read, that—
Fluttering his pinions vain,
Plumb down he dropped, ten thousand fathoms deep.’
Whether our power of conceiving is so far a test of possibility, as that what is distinctly conceived must be concluded to be possible, and what cannot be conceived impossible, was a question which interested Reid. It is discussed in the Essays on the Intellectual Powers, and also in the draft of a letter to Dr. Price, preserved among the manuscripts at Birkwood; in which it is argued that our power of conception cannot be a criterion of what is possible. The argument turns much on the meanings of 'conception,' 'possibility,' and 'impossibility.' He thus addresses Dr. Price:—
'I would willingly suggest some subject on which I might have the favour of your thoughts when you have leisure and are disposed for such correspondence. What occurs to my thoughts just now is a metaphysical axiom very generally adopted, and, I think, occasionally adopted by you in your Review of the Principal Questions in Morals—That what we distinctly conceive is possible. From this axiom D. Hume infers that it is possible that an universe may start into existence without a cause, and other like extravagancies. The use he makes of it led me to consider it a good many years ago, and I have a strong suspicion that there is some fallacy in it, which has imposed on men’s understandings, owing to the ambiguity of the word conceive.
