By the facility, with which we can in our waking hours voluntarily produce certain successive trains of ideas, we know by experience, that we have before reproduced them; that is, we are conscious of a time of our existence previous to the present time; that is, of our identity now and heretofore. It is these habits of action, these catenations of ideas and muscular motions, which begin with life, and only terminate with it; and which we can in some measure deliver to our posterity; as explained in Sect. XXXIX.
6. When the progressive motions of external bodies make a part of our present catenation of ideas, we attend to the lapse of time; which appears the longer, the more frequently we thus attend to it; as when we expect something at a certain hour, which much interests us, whether it be an agreeable or disagreeable event; or when we count the passing seconds on a stop-watch.
When an idea of our own person, or a reflex idea of our pleasures and pains, desires and aversions, makes a part of this catenation, it is termed consciousness; and if this idea of consciousness makes a part of a catenation, which we excite by recollection, and know by the facility with which we excite it, that we have before experienced it, it is called identity, as explained above.
7. In respect to freewill, it is certain, that we cannot will to think of a new train of ideas, without previously thinking of the first link of it; as I cannot will to think of a black swan, without previously thinking of a black swan. But if I now think of a tail, I can voluntarily recollect all animals, which have tails; my will is so far free, that I can pursue the ideas linked to this idea of tail, as far as my knowledge of the subject extends; but to will without motive is to will without desire or aversion; which is as absurd as to feel without pleasure or pain; they are both solecisms in the terms. So far are we governed by the catenations of motions, which affect both the body and the mind of man, and which begin with our irritability, and end with it.
Haud equidem credo, quia sit divinitus illis Ingenium, aut rerum fato prudentia major.--Virg. Georg. L. I. 415.
I. _Instinctive actions defined. Of connate passions._ II. _Of the sensations and motions of the foetus in the womb._ III. _Some animals are more perfectly formed than others before nativity. Of learning to walk._ IV. _Of the swallowing, breathing, sucking, pecking, and lapping of young animals._ V. _Of the sense of smell, and its uses to animals. Why cats do not eat their kittens._ VI. _Of the accuracy of sight in mankind, and their sense of beauty. Of the sense of touch in elephants, monkies, beavers, men._ VII. _Of natural language._ VIII. _The origin of natural language;_ 1. _the language of fear;_ 2. _of grief;_ 3. _of tender pleasure;_ 4. _of serene pleasure;_ 5. _of anger;_ 6. _of attention._ IX. _Artificial language of turkies, hens, ducklings, wagtails, cuckoos, rabbits, dogs, and nightingales._ X. _Of music; of tooth-edge; of a good ear; of architecture._ XI. _Of acquired knowledge; of foxes, rooks, fieldfares, lapwings, dogs, cats, horses, crows, and pelicans._ XII. _Of birds of passage, dormice, snakes, bats, swallows, quails, ringdoves, stare, chaffinch, hoopoe, chatterer, hawfinch, crossbill, rails and cranes._ XIII. _Of birds nests; of the cuckoo; of swallows nests; of the taylor bird._ XIV. _Of the old soldier; of haddocks, cods, and dog fish; of the remora; of crabs, herrings, and salmon._ XV. _Of spiders, caterpillars, ants, and the ichneumon._ XVI. 1. _Of locusts, gnats;_ 2. _bees;_ 3. _dormice, flies, worms, ants, and wasps._ XVII. _Of the faculty that distinguishes man from the brutes._