Murder, Incest, Stabbing

Locke begins the third book of An Essay Concerning Human Understanding by arguing that knowledge is founded on fairly certain simple ideas that represent sensible qualities. So far, it seems, so Cartesian. But Locke is also aware that the mind freely constructs certain concepts out of the simple ideas, and assigns words to these concepts. These words and concepts are not applied to natural substances but rather to complex social institutions. He calls them “mixed modes,” and offers several examples:

” A little looking into them will satisfy us, that it is the mind that combines several scattered independent ideas into one complex one; and, by the common name it gives them, makes them the essence of a certain species, without regulating itself by any connexion they have in nature. For what greater connexion in nature has the idea of a man than the idea of a sheep with killing, that this is made a particular species of action, signified by the word murder, and the other not? Or what union is there in nature between the idea of the relation of a father with killing than that of a son or neighbour, that those are combined into one complex idea, and thereby made the essence of the distinct species parricide, whilst the other makes no distinct species at all? But, though they have made killing a man’s father or mother a distinct species from killing his son or daughter, yet, in some other cases, son and daughter are taken in too, as well as father and mother: and they are all equally comprehended in the same species, as in that of incest. Thus the mind in mixed modes arbitrarily unites into complex ideas such as it finds convenient; whilst others that have altogether as much union in nature are left loose, and never combined into one idea, because they have no need of one name. It is evident then that the mind, by its free choice, gives a connexion to a certain number of ideas, which in nature have no more union with one another than others that it leaves out: why else is the part of the weapon the beginning of the wound is made with taken notice of, to make the distinct species called stabbing, and the figure and matter of the weapon left out?”

Locke denies that his theory makes the formation of these complex ideas arbitrary, but he does insist that “it is done by the free choice of the mind, pursuing its own ends.” And he insists that in the formation of complex ideas the mind is creative: It “searches not its patterns in nature, nor refers the ideas it makes to the real existence of things, but puts such together as may best serve its own purposes, without tying itself to a precise imitation of anything that really exists.”