Certain alterations, also, are observed in those parts of clusters on which such and such effects depend; which alterations make corresponding alterations in the effects, though no other alteration is observable, in the cluster, to which such parts belong. Thus, if a stone is more or less hot, the effects or successions are not the same; so of iron, so of lead; but the same alteration in the same part of each of those clusters, is followed by the same effects. It is true, that we know nothing of the alteration in the cause, but by the alteration in the effects; for we only say that a stone is hotter, because it produces such other effects, either in our sensations immediately, or in the sensations we receive from other objects. It is, however, obvious that we have urgent use for the means of marking, not only the alterations in the effects, but the alterations in the antecedents. This we do, by supposing the alterations to be those of increase and diminution, and marking them by the distinction of lower and higher degrees. But, for this purpose, it is obvious that we must have a term which is not connotative; because we suppose no alteration in any 316 part of the cluster but that which is not connoted; thus we can say, with sufficient precision, that a greater or less degree of heat produces such and such effects; but we cannot say, that a greater or less degree of hot stone, of hot iron, of hot any thing else, produces these effects.
This then, is another use, and evidently a most important use, of abstract, non-connotative terms. They enable us to mark, with more precision, those successions, in which our good and evil is wholly contained.
This also enables us to understand, what it is which recommends such and such aggregates, and not others, for classification. Those successions of objects, in which we are interested, determine the classifications which we form of them.
Some successions are found to depend upon the clusters, called objects, all taken together. Thus a tree, a man, a stone, are the antecedents of certain consequents, as such; and not on account of any particular part of the cluster.
Other consequents depend not upon the whole of the cluster, but upon some particular part: thus a tall tree, produces certain effects, which a tree not tall, cannot produce; a strong man, produces certain effects, which a man not strong cannot produce. When these consequents are so important, as to deserve particular attention, they and their antecedents must be marked. For this purpose, are employed the connotative terms marking differences. These terms enable us to group the clusters containing those antecedents into a sub-class; and NON-CONNOTATIVE or ABSTRACT terms, derived from them, enable 317 us to speak separately of that part of the cluster which we have to mark as the precise antecedent of the consequent which is engaging our attention.
It is presumed, that these illustrations will suffice, to enable the reader to discern the real marking power of abstract terms, and also to perceive the mode of their formation.
CHAPTER X.
MEMORY.
“The science of metaphysics, as it regards the mind, is, in its most important respects, a science of analysis; and we carry on our analysis, only when we suspect that what is regarded by others as an ultimate principle, admits of still finer evolution into principles still more elementary.”—Inquiry into the Relation of Cause and Effect, by Thomas Brown, M.D. P. iv. s. i. p. 331.