Here all the nouns are general, but the picture is individual and concrete. It is also quite intelligible, as a sketch. We can think of a man without assigning to him any particular type of face, or colour of hair, or stature, or age, or clothing. Our idea is the general idea _man_ used as a sketch of a particular man. He is in a house because he is looking through a window, but we do not stay to imagine the house as cottage, inn, or mansion. We call up the general idea _house_, which is definite enough for our purpose, and we cannot doubt for a moment that we have such a general idea. The river may be wide or narrow, straight or crooked, navigable or not, but we think only of the general idea _river_, which is water flowing between banks. And surely we can imagine a general _city_ without giving it any definite size, or form, or nationality, or number of inhabitants! These considerations clearly demonstrate that we have general ideas, which are not merely concrete ideas used as examples, and if we can employ them in the manner just indicated, where a light superficial recollection is all that is necessary, we can equally well use them in their more legitimate character, as signs of certain general utilities. XV--ERRORS WITH RESPECT TO GENERALISATION Generalisation has been the bane of European philosophy. It has monopolised well-nigh the whole metaphysical attention. It has been considered the radical fact of mind from which all others have grown, whereas it is no more than a method for abbreviating recollection. It neither reveals to us new things, nor reduces the multiplicity of things actually existing. Plato insisted on the importance of general thought as against the fluctional idealism of Heraclitus, but he was wholly mistaken as to the nature of general ideas. He thought they were external objects--also types and causes of primary objects. But patterns are not causes, and general ideas are quite obviously suggested by things, not things derived from general ideas. The notion that the general idea is either the cause, or an image and revelation of the cause, of things is an error of perennial recurrence. In some form or other it is always with us. Plato also taught that general ideas are recollections of knowledge acquired in the condition prior to embodiment, which the objective experience of this life serves to revive. These several doctrines are somewhat inconsistent with each other. The last is interesting but lacks confirmation. Aristotle admitted the superiority of general over particular ideas, and thought that the former corresponded to some specially important part of objects called the 'essence.'