INSTINCT 139 



perience and involves memory; where there is memory, 

 there is some kind of consciousness. One is willing to admit 

 that at this level, where the quality of all stimuli is monoto- 

 nously the same (judged by response), consciousness is an 

 ephemeral obscurity; but it is emergent consciousness, nev- 

 ertheless. 



The second stage in the evolution of behavior gradually 

 appears in the worms. Theirs is a world of definite objects, 

 occupying space and having size and shape and degrees of 

 solidity. With their limited sensory equipment worms are 

 able to "visualize" something of the framework of their 

 environment, but space and time are still very circum- 

 scribed. Light is interpreted as heat on the body, and the 

 knowledge of objects is limited to contact. Nevertheless, 

 worms have a definite spatial sense of right and left and, 

 as we have noted, are capable of learning a T maze. 



With the advent of image-forming eyes instead of the 

 sensitized pigment of the lower forms, the world suddenly 

 expands, especially with the gradual evolution of a brain 

 more capable of linking other senses, such as touch and 

 smell and hearing. This is to become the world of the third 

 stage— a world of space and time, infinite and eternal, and 

 of cause and effect and orderliness of construction. The in- 

 sects and vertebrates begin to occupy the fringes of this 

 world. Some definitely move toward a substantial posses- 

 sion of the world of space and time, but it remains for man 

 to explore it fully. 



This chapter examines the instinct phase by which ani- 

 mals attempt to occupy the expanding world stage. In the 

 higher vertebrates, particularly man, instinct is rarely ma- 

 chine-like; it is a flexible response in regard to the situations 

 which call it up and to the manner of meeting them. In man 

 the impulsion of fear or anger compels a general reaction to 

 a general situation; it is a highly flexible complex of re- 

 sponses. In insects one sees instinct in its truest sense, in 

 some cases almost completely inflexible, called up specifi- 



