’Tis the same, he would say, throughout the whole circle of the sciences; --the great, the established points of them, are not to be broke in upon. --The laws of nature will defend themselves; --but error----(he would add, looking earnestly at my mother)----error, Sir, creeps in thro’ the minute holes and small crevices which human nature leaves unguarded. This turn of thinking in my father, is what I had to remind you of: --The point you are to be informed of, and which I have reserved for this place, is as follows. Amongst the many and excellent reasons, with which my father had urged my mother to accept of Dr. _Slop’s_ assistance preferably to that of the old woman, ----there was one of a very singular nature; which, when he had done arguing the manner with her as a Christian, and came to argue it over again with her as a philosopher, he had put his whole strength to, depending indeed upon it as his sheet-anchor. ----It failed him; tho’ from no defect in the argument itself; but that, do what he could, he was not able for his soul to make her comprehend the drift of it. ----Cursed luck! ----said he to himself, one afternoon, as he walked out of the room, after he had been stating it for an hour and a half to her, to no manner of purpose; --cursed luck! said he, biting his lip as he shut the door, ----for a man to be master of one of the finest chains of reasoning in nature, --and have a wife at the same time with such a headpiece, that he cannot hang up a single inference within side of it, to save his soul from destruction. This argument, though it was entirely lost upon my mother, ----had more weight with him, than all his other arguments joined together: --I will therefore endeavour to do it justice, --and set it forth with all the perspicuity I am master of. My father set out upon the strength of these two following axioms: _First_, That an ounce of a man’s own wit, was worth a ton of other people’s; and, _Secondly_ (Which by the bye, was the ground-work of the first axiom, ----tho’ it comes last), That every man’s wit must come from every man’s own soul, ----and no other body’s. Now, as it was plain to my father, that all souls were by nature equal, ----and that the great difference between the most acute and the most obtuse understanding----was from no original sharpness or bluntness of one thinking substance above or below another, ----but arose merely from the lucky or unlucky organisation of the body, in that part where the soul principally took up her residence, ----he had made it the subject of his enquiry to find out the identical place.