Of Memory her ideal train preserves
Entire; or, when they would elude her watch,
Reclaims their fleeting footsteps, from the waste
Of dark Oblivion.”[141]
What then are these mysterious ties?—or, to state the question more philosophically, what are the general circumstances which regulate the successions of our ideas?
That there is some regularity in these successions, must, as I have already remarked, have been felt by every one; and there are many references to such regularity in the works of philosophers of every age. The most striking ancient reference, however, to any general circumstances, or laws of suggestion,—though the innumeration of these is hinted, rather than developed at any length,—is that which you will find in a passage, quoted by Dr Beattie and Mr Stewart, from Aristotle. It is a passage explanatory of the process by which, in voluntary reminiscence, we endeavour to discover the idea of which we are in search. We are said to hunt for it—(Θηρεὺομεν is the word in the original)—among other ideas, either of objects existing at present, or at some former time; and from their resemblance, contrariety, and contiguity— ἀπὸ τοῦ νῦν, ἢ ἂλλου τινὸς, καὶ ἀφ' ὁμοίου, ἢ ἐναντίου, ἢ τοῦ συνέγγυς. Διὰ τοῦτο γινεταὶ ἡ ἀνάμνησις.[142] This brief enumeration of the general circumstances which direct us in reminiscence is worthy of our attention on its own account; and is not less remarkable on account of the very close resemblance which it bears to the arrangement afterwards made by Mr Hume, though there is no reason to believe that the modern philosopher was at all acquainted with the classification which had, at so great a distance of time, anticipated his own.
I must remark, however, that though it would be in the highest degree unjust to the well-known liberality and frankness of Mr Hume's character, to suppose him to have been aware of any enumeration of the general circumstances on which suggestion appears to depend, prior to that which he has himself given us, his attempt was far from being so original as he supposed. I do not allude merely to the passage of Aristotle, already quoted, nor to a corresponding passage, which I might have quoted, from one of the most celebrated of his commentators, Dr Thomas Aquinas, but to various passages which I have found in the works of writers of much more recent date, in which the influence of resemblance and contiguity, the two generic circumstances to which, on his own principles, his own triple division should have been reduced, is particularly pointed out. Thus, to take an example from an elementary work of a very eminent author, Ernesti, published in the year 1734,—his Initia Doctrinæ Solidioris,—with what precision has he laid down those very laws of association of which Mr Hume speaks. After stating the general fact of suggestion, or association, under the Latin term phantasia, he proceeds to state the principles which guide it. All the variety of these internal successions of our ideas, he says, may be reduced to the following law. When one image is present in the mind, it may suggest the image of some absent object—either of one that is similar in some respect to that already present—or of one of which the present is a part—or of one which has been present together with it on some former occasion. “Hujus autem phantasiæ lex hæc est; Præsentibus animo rerum imaginibus quibuscunque, recurrere et redire ad animum possunt rerum absentium olimque perceptarum imagines, præsentibus similes, vel quarum, quæ sunt præsentes, partes sunt,—vel denique, quas cum præsentibus simul hausimus.”[143]
Even the arrangement, as stated by Mr Hume, is not expressed in more formal terms. But as it is to his arrangement the philosophers of our own country are accustomed to refer, in treating of association, the importance thus attached to it gives it a preferable claim to our fuller discussion. It is stated by him briefly in two paragraphs of his Essay on the Association of Ideas.
“Though it be too obvious to escape observation,” he says, “that different ideas are connected together, I do not find that any philosopher has attempted to enumerate or class all the principles of association; a subject, however, that seems worthy of curiosity. To me there appear to be only three principles of connexion among ideas, viz. resemblance, contiguity in time or place, and cause or effect.
“That these principles serve to connect ideas, will not, I believe, be much doubted. A picture naturally leads our thoughts to the original. The mention of one apartment in a building naturally introduces an inquiry or discourse concerning the others. And if we think of a wound, we can scarcely forbear reflecting on the pain which follows it. But that the enumeration is complete, and that there are no other principles of association except these, may be difficult to prove to the satisfaction of the reader or even to a man's own satisfaction. All we can do, in such cases, is to run over several instances, and examine carefully the principle which binds the different thoughts to each other,—never stopping, till we render the principle as general as possible. The more instances we examine, and the more care we employ, the more assurance shall we acquire, that the enumeration which we form from the whole is complete and entire.”[144]