INTUITIVE AND ACQUIRED PERCEPTIONS. 533 



whioh may not be corrected, until we have ascertained by the touch, 

 the flatness of the real object. 



937. This production of ideas, by the agency of sensations, is a pro- 

 cess altogether mental, and dependent upon the laws of Mind. We 

 find that some of these perceptions or elementary notions are intuitive : 

 that is, they are prior to all experience, and are as necessarily connected 

 with the sensation which produces them, as reflex movements are with 

 the impression that excites them. This seems to be the case, for 

 example, with regard to erect vision. There is no reason whatever to 

 think, that either infants or any of the lower animals see objects in an 

 inverted position, until they have corrected their notion by the touch ; 

 for there is no reason why- the inverted picture on the retina should 

 give rise to the idea of the inversion of the object. The picture is so 

 received by the mind, as' to convey to us an idea of the position of 

 external objects, which harmonizes with the ideas we derive through the 

 touch ; and whilst we are in such complete ignorance of the manner in 

 which the mind becomes conscious of the sensation at all, we need not 

 feel any' difficulty about the mode in which this conformity is effected. 

 But in Man, as already stated, the attaching definite ideas to certain 

 groups of lines, colours, &c., with respect to the objects they represent, 

 is a subsequent process, in which experience and memory are essentially 

 concerned ; as we see particularly well, in cases presently to be referred 

 to, in which the sense of sight has been acquired comparatively late in 

 life, and in which the mode of using it, and of connecting the sensa- 

 tions received through it with those received through the touch, has 

 had to be learned, by a long-continued training. The elementary 

 notions thus formed, which may, by long habit, present themselves as 

 immediately and unquestionably, as if they were intuitive, are termed 

 acquired perceptions. 



938. It is probable that, among th'e lower animals, the proportion of 

 intuitive perceptions is much greater than in Man ; whilst, on the other 

 hand, his power of acquiring perceptions is much greater than theirs. 

 So that, whilst the young of the lower animals very soon becomes pos- 

 sessed of all the knowledge which is necessary for the acquirement of 

 its food, the construction of its habitation, &c., its range is very limited, 

 and it is incapable of attaching any ideas to a great variety of objects, 

 of which the Human mind takes cognizance. This correspondence 

 between the acquired perceptions of Man, and^the intuitive perceptions 

 of many of the lower animals, is strikingly evident in regard to the 

 power of measuring distance. This is acquired very gradually by the 

 Human infant, or by a person who has first obtained the faculty of 

 sight later in life ; but it is obviously possessed by many of the lower 

 animals, to whose maintenance it is essential, immediately upon their 

 entrance into the world. Thus, a Fly-catcher, immediately after its 

 exit from the egg, has been known to peck at and capture an insect, 

 an action which requires a very exact appreciation of distance, as well 

 as a power of precisely regulating the muscular movements in accordance 

 with it. 



