The first kind is derived from real existences that have been objects of our senses; _language is the cause of the second_, or any other sign that has the same power with language; and a man's imagination is to himself the cause of the third.

It is scarce [ly] necessary to add, that an idea, originally of imagination, being conveyed to others by language or any other vehicle, becomes in their mind an idea of the second kind; and again, that an idea of this kind, being afterwards recalled to the mind, becomes in that circumstance an idea of memory."-- _El.

of Crit._, Vol.

ii, p.

384.
5.