A MAN while awake is sensible of a continued train of objects passing in his mind. It requires no activity on his part to carry on the train: nor has he power to vary it by calling up an object at will[6]. At the same time we learn from daily experience, that a train of thought is not merely casual. And if it depend not upon will, nor upon chance, we must try to evolve by what law it is governed. The subject is of importance in the science of human nature; and I promise beforehand, that it will be found of great importance in the fine arts.
It appears that the relations by which things are linked together, have a great influence in directing the train of thought; and we find by experience, that objects are connected in the mind precisely as they are externally. Beginning then with things external, we find that they are not more remarkable by their inherent properties than by their various relations. We cannot any where extend our view without perceiving things connected together by certain relations. One thing perceived to be a cause, is connected with its several effects; some things are connected by contiguity in time, others by contiguity in place; some are connected by resemblance, some by contrast; some go before, some follow. Not a single thing appears solitary, and altogether devoid of connection. The only difference is, that some are intimately connected, some more slightly; some near, some at a distance.
Experience as well as reason may satisfy us, that the train of mental perceptions is in a great measure regulated by the foregoing relations. Where a number of things are linked together, the idea of any one suggests the rest; and in this manner is a train of thoughts composed. Such is the law of succession; whether an original law, or whether directed by some latent principle, is doubtful; and probably will for ever remain so. This law, however, is not inviolable. It sometimes happens, though rarely, that an idea presents itself to the mind without any connection, so far at least as can be discovered.
But though we have not the absolute command of ideas, yet the Will hath a considerable influence in directing the order of connected ideas. There are few things but what are connected with many others. By this means, when any thing becomes an object, whether in a direct survey, or ideally only, it generally suggests many of its connections. Among these a choice is afforded. We can insist upon one, rejecting others; and we can even insist upon what has the slightest connection. Where ideas are left to their natural course, they are generally continued through the strongest connections. The mind extends its view to a son more readily than to a servant, and more readily to a neighbour than to one living at a distance. This order may be varied by Will, but still within the limits of connected objects. In short, every train of ideas must be a chain, in which the particular ideas are linked to each other. We may vary the order of a natural train; but not so as to dissolve it altogether, by carrying on our thoughts in a loose manner without any connection. So far doth our power extend; and that power is sufficient for all useful purposes. To give us more power, would probably be detrimental instead of being salutary.
Will is not the only cause that prevents a train of thought from being continued through the strongest connections. Much depends on the present tone of mind; for a subject that accords with this tone is always welcome. Thus, in good spirits, a chearful subject will be introduced by the slightest connection; and one that is melancholy, not less readily in low spirits. Again, an interesting subject is recalled, from time to time, by any connection indifferently, strong or weak. This is finely touched by Shakespear, with relation to a rich cargo at sea.
My wind, cooling my broth,
Would blow me to an ague, when I thought
What harm a wind too great might do at sea.
I should not see the sandy hour-glass run,
But I should think of shallows and of flats;
And see my wealthy Andrew dock’d in sand,
Vailing her high top lower than her ribs,
To kiss her burial. Should I go to church,
And see the holy edifice of stone,
And not bethink me strait of dangerous rocks?
Which touching but my gentle vessel’s side,
Would scatter all the spices on the stream,
Enrobe the roaring waters with my silks,
And, in a word, but now worth this,
And now worth nothing.
Merchant of Venice, act 1. sc. 1.
Another cause clearly distinguishable from that now mentioned, hath also a considerable influence over the train of ideas. In some minds of a singular frame, thoughts and circumstances crowd upon each other by the slightest connection. I ascribe this to a defect in the faculty of discernment. A person who cannot accurately distinguish betwixt a slight connection and one that is more solid, is equally affected with both. Such a person must necessarily have a great command of ideas, because they are introduced by any relation indifferently; and the slighter relations, being without number, must furnish ideas without end. This doctrine is, in a lively manner, illustrated by Shakespear.
Falstaff. What is the gross sum that I owe thee?
Hostess. Marry, if thou wert an honest man, thyself and thy money too. Thou didst swear to me on a parcel-gilt goblet, sitting in my Dolphin chamber, at the round table, by a sea-coal fire, on Wednesday in Whitsun-week, when the Prince broke thy head for likening him to a singing man of Windsor, thou didst swear to me then, as I was washing thy wound, to marry me, and make me my Lady thy wife. Canst thou deny it? Did not Goodwife Keech, the butcher’s wife, come in then, and call me Gossip Quickly? Coming in to borrow a mess of vinegar; telling us she had a good dish of prawns; whereby thou didst desire to eat some; whereby I told thee they were ill for a green wound? And didst not thou, when she was gone down stairs, desire me to be no more so familiarity with such poor people, saying, that ere long they should call me Madam? And didst thou not kiss me, and bid me fetch thee thirty shillings? I put thee now to thy book-oath, deny it if thou canst.
Second part, Henry IV. act 2. sc. 2.