making use of a science, which can only be brought to bear on moral science as a means of illustrating it, and abbreviating the method of reasoning, as affording "rounds for reasoning by analogy. Perhaps, on a fair consideration, Hutcheson may not have intended to carry his system to the extent presumed in this valuable little treatise, most of the arguments of which are made to meet the application of the mathematics, not only as forming a regular series of analogies fit to be used in moral science, but likewise as so accurately corresponding, that, as it is all mensurable itself, it serves the purpose of a measurer in moral science. The following sentence contains the essence of his argument on this last point, and it is conclusive. "It is not easy to say how many kinds of improper quantity may, in time, be introduced into the mathematics, or to what new subjects measures may be applied: but this, I think, we may conclude, that there is no foundation in nature for, nor can any valuable end be served by, applying measure to any thing but what has these two properties : First, it must admit
of degrees of greater and less; secondly, it must be associated with or related
to something that has proper quantity, so as that when one is increased, the
other is increased; when one is diminished, the other is diminished also; and
every degree of the one must have a determinate magnitude or quantity of the
other corresponding to it."[1] Reid seems not to have been very certain whether
the person whom he opposes, (styled by him Dr M.,) did actually maintain
mathematics as being a proper measure in the moral sciences, or that it merely
afforded useful analogies ; and perhaps some who are disposed to agree with Reid
as to the former alternative, may not be prepared to join him in attacking the
latter. He continues: "Though attempts have been made to apply mathematical reasoning to some of these things, and the quantity of virtue and merit in actions has been measured by simple and compound ratios; yet Dr M. does not
think that any real knowledge has been struck out this way: it may, perhaps,
if discreetly used, be a help to discourse on these subjects, by pleasing the
imagination, and illustrating what is already known ; but till our affections and
appetites shall themselves be reduced to quantity, and exact measures of their
various degrees be assigned, in vain shall we essay to measure virtue and merit
by them. This is only to ring changes on words, and to make a show of mathematical reasoning, without advancing one step in real knowledge."[2]
In 1752, the professors of King's college in Aberdeen, elected Dr Reid professor of moral philosophy, "in testimony of the high opinion they had formed of his learning and abilities." After having taken up his residence in Aberdeen, he became one of the projectors of that select society of philosophers, which then dignified the northern city. It is perhaps partly to the influence of this association, that, among many other works, we owe the "Inquiry into the Human Mind upon the Principles of Common Sense," which Dr Reid published in 1764. As this work developed an argument against the sceptical philosophy of Mr Hume, the author, with more magnanimity than some members of his profession displayed at the time, procured, by the interposition of Dr Blair, a perusal of the manuscript by Hume, in order that any of those disputes, from mere misunderstanding of words, so pernicious to philosophical discussion, might be avoided. Hume at first displayed some disinclination, founded on previous experience of others, to encourage this new assailant. "I wish," he said, "that the parsons would confine themselves to their old occupation of worrying one another, and leave philosophers to argue with tem-
- ↑ Reid's Essays, (1820,) vi.
- ↑ Essays, viii. Stewart, who praises the principles of this Essay, (Life ut sup. 510,) was more than most philosophers of his eminence, addicted to the vice detected in one of its forms, viz., comparison between mental and physical nature, not merely to the extent of illustration, but of analogy.
