76 PROF. J. ARTHUR THOMSON ON 
This is a favourite theory, and there isa strong element of 
truth in it, but as an all-sufficient explanation the imitation- 
theory will not work. I hardly think one can explain the 
doll-play of the daughter of a house, who is an only child, as 
wholly imitative. A kitten taken very early from the 
mother will play profusely without any known _possi- 
bility of imitative stimulus. The subtler games of our 
children are often imitations of our industry, but I do not 
think that we can generalise this. 
The other theory of play is Darwinian, and Groos has the 
credit of having developed it. According to this theory, 
there are play-instincts, which may be stimulated by super- 
fluous energy; these play-instincts have been gradually 
established and strengthened by the elimination of the bad 
players (in subsequent life-struggle). Play is justified in the 
economy of nature in two ways; firstly, because it is the 
apprenticeship to future work, the training school for serious 
efforts, or the rehearsal before the real performance; and 
secondly, because intellectual development probably flourishes 
better in proportion as the brain is freed from the necessity 
of bearing with it the hereditary mechanism for the perfect 
performance of certain activities. If play can perfect any 
instinctive activity before failure is vital, the weight of a 
stereotyped inheritance is lessened. 
We may go a step further. 
Play is more than the apprenticeship, the rehearsal, 
introductory to future life and work. It is more than a 
means whereby the brain may be freed from some of its 
hereditary burden. It is one of the few opportunities which 
afford free scope for variations without too rigorous selection. 
This is of very great importance, especially as regards the 
practical outlook of man, and perhaps also as regards the 
origin of art. In the real business of life, most initiatives— 
“new departures,” “ idiosyncrasies,” variations—are the sub- 
ject of rigorous selection, which often nips in the bud vital 
initiatives worth cherishing, Play is Nature’s device for 
granting elbow-room for those variations which form or 
may form part of the raw materials of progress. 
