io8 Unconscious Memory 



become a chrysalis, it spins for itself a double cocoon, 

 fortified with bristles that point outwards, so that it can 

 be opened easily from within, though it is sufficiently im- 

 penetrable from without. If this contrivance were the 

 result of conscious reflection, we should have to suppose 

 some such reasoning process as the following to take place 

 in the mind of the caterpillar : — " I am about to become 

 a chrysalis, and, motionless as I must be, shall be exposed 

 to many different kinds of attack. I must therefore weave 

 myself a web. But when I am a moth I shaU not be able, 

 as some moths are, to find my way out of it by chemical 

 or mechanical means ; therefore I must leave a way 

 open for myself. In order, however, that my enemies 

 may not take advantage of this, I will close it with elastic 

 bristles, which I can easily push asunder from within, 

 but which, upon the principle of the arch, will resist all 

 pressure from without." Surely this is asking rather 

 too much from a poor caterpillar ; yet the whole of the 

 foregoing must be thought out if a correct result is to be 

 arrived at. 



This theoretical separation of instinct from conscious 

 intelligence can be easily misrepresented by opponents of 

 my theory, as though a separation in practice also would 

 be necessitated in consequence. This is by no means 

 my intention. On the contrary, I have already insisted 

 at some length that both the two kinds of mental activity 

 may co-exist in all manner of different proportions, so that 

 there may be every degree of combination, from pure in- 

 stinct to pure deliberation. We shall see, however, in a 

 later chapter, that even in the highest and most abstract 

 activity of human consciousness there are forces at work 

 that are of the highest importance, and are essentially 

 of the same kind as instinct. 



On the other hand, the most marvellous displays of 

 instinct are to be found not only in plants, but also in 

 those lowest organisms of the simplest bodily form which 

 are partly unicellular, and in respect of conscious intelli- 



