14 ANIMAL INTELLIGENCE 
which men are agreed, it is that its performances are 
inexplicable, either to the individual himself or to 
others, in at all events, the most remarkable cases. 
Take as instances in very different lines of thought 
Newton’s perceptions of quantity and space relations, 
and Mozart’s of tone relations. These perceptions were 
immediate, and surmounted all ordinary rules of mental 
movement. But when a homing pigeon covers 500 
miles in so short a time that the rate of speed rises to 
40 or 50 miles an hour, showing how straight is the 
path by which it reaches its home, we are ready to class 
the performance as wonderful for a bird, but not on a 
par with any feat of human genius. So far as I know, 
no one has as yet explained such a performance. I 
have studied this subject, and made some experi- 
ments with homing pigeons, but whether we explain 
the matter as the exercise of very accurate perceptions 
of landmarks—which is not an explanation without 
great difficulties when long distances are involved—or 
whether we give up the problem and say we have no 
experience which enables us to understand it—the 
result is still marvellous, and is closer to the per- 
formance, of genius than anything else to which it can 
be compared. Itis to be remembered, too, that we may 
find even in imbeciles or idiots certain psychic capa- 
bilities as, e.g. for music, developed to an amazing extent, 
so that the generally low intelligence of a pigeon is not 
to be set up as a plea of belittlement of its homing 
performance. 
Therefore, while man is a law unto himself, and to a 
certain extent a law to all other creatures, while he 
must look within to understand himself and use intro- 
spection in attempting to get at the nature of the 
psychic life of the lower animals, he must also recognise 
the limitations of this final method, and realise that he 
may stumble on problems regarding both himself (in 
