their connexion with confequences, cither neceffarily or probably refulting from the preexistence of those states only, and not from any other cause.

762. The fenfations received from the fight or hearing, are almost the only states of which the ideas can be fully recovered, at least after a long interval. The ideas of taste or smell are little more than instantaneous; the ideas of rough and smooth are more durable; but the fenfations of heat or cold, hunger or thirst, or other sufferings, cannot be expressly recovered; their existence can only be traced from their figns, affociated circumstances, and refulting confequences: thus alfo the knowledge of pre-exifting notions is revived, and also the discernment of relations, judgments, argumentations, volitions, emotions, or paffions previously had.

763. Signs are either natural, as fighs, groans, &c.; or conventional, as words, whether spoken or written; and as these are either vocal or vifible, they are most easily remembered, and through them the things they fignify.

764. Memory may be confidered in a double point of view; either as the capacity of re

ceiving

ceiving ideas or their signs, as already faid; or as the facility of recollecting them: this however requires the concurrence of the will, at leaft in common cafes, for certain ftrong emotions, fuch as thofe of grief, anger, and remorse, may even unwillingly be renewed. Both the capacity of receiving, and the power of recollecting ideas, are poffeffed by different minds in degrees aftonishingly different.

765. That memory is fome how connected with organization, that is a peculiar arrangement of obscure fenfations, is certain, from its general decay in old age, and in confequence of various disorders by which fome of those obfcure fenfations are effaced, but the mode of connexion is perfectly unknown. I Crichton, 358.

See

766. Imagination is the power of compounding, curtailing, and arranging ideas, and of combining the figns, whether of ideas or of other mental operations, in an intelligible manner, different from the arrangement, according to which fenfations, of which they are the copies, were originally impressed; and in this it differs from memory.

767. I call it a power, because it commonly includes an act of the will; yet its represen tations

tations fometimes arife involuntarily, by reafon of fome early affociation, or fear, &c. as when spectres or other frightful objects are imagined in the dark.

768. The only ideas which the imagination can command, are those of visible or audible objects; of other fenfations it can prefent only their figns, which are themselves visible or audible; yet these signs affect us nearly, if not fully, as much, as the ideas of the objects they fignify could: this must be evident to any one who confiders the words, fragrant, bitter, fweet, four, fharp, blunt, bot, cold, painful; nay even the ideas of visible or audible objects are not always neceffary; their figns, when we are long accustomed to their connexion with the things fignified, are fully fufficient; for, from long experience of their intimate affociation, their effects on the imagination become identified; thus money, though merely a fign, is as much coveted as the things it can purchase or procure, though it fuggefts none of them in particular; Mr. Locke justly obferves, that we frequently think by words and not by ideas.

SECT.

SECT. V.

OF SIMPLE APPREHENSION, CONCEPTION, AND

COMPREHENSION.

769. Simple apprehenfion was a term anciently used by the fcholaftics to denote the mere idea of a sensible object, without affirming or denying any thing concerning it: it was never applied to fictions of imagination, and but feldom to notions, which they called intellections. See Pourchot, Log. 46.

770. Conception anciently, at least for the moft part, denoted an idea generalized; thus the nominalists called the idea of a circle, when representing all circles, the conception of a circle, from cum et capere; but at present it is taken for an idea, or intellection; thus profeffor Stewart calls it an exact tranfcript of what we have felt or perceived; Phil. of the Mind, p. 135. And by intellection I mean a knowledge of the fignification of figns, such as words or propofitions, or the meaning of notions; as when I fay I conceive God to be a neceffary being; I conceive virtue to consist in conformity to his will; I conceive the meaning of the word chilibadron,

chilihedron, but can form no idea of it; that is, I understand the meaning of the word God to be, that he is a neceffary being; and that of the word virtue to be conformity to his will. When we speak of conceiving or understanding a general propofition, we mean nothing more, (as Mr. Stewart juftly obferves, p. 196,) than that we have a conviction that we have it in our power to fubftitute, inftead of the general terms, fome one of the individual inftances comprehended under them.

771. To comprehend, is frequently taken in the fame fenfe as to conceive or understand, but, as I think, improperly, except when it is ufed to denote understanding a series of propofitions. In logic, it denotes all that a term, particularly a general term, can fignify thus the term animal comprehends all animals.* In metaphyfics, it denotes the knowledge of all the properties of an object.

* 5 Pourchot, 10. 269. 1 Pourchot, 6o. Segui Log. 81, 82. III.