PHYSICAL ANTECEDENTS OF SCIENCE 135

are conditions indispensable for science, because they are

conditions indispensable for sensation, but also make it clear

what admirable results may proceed from causes seemingly

most inadequate.

The different " tissues " of our body are so combined as to

form efficient " organs," different sets of which are combined

into systems the activities of the tissues, organs, and

systems harmoniously resulting in the performance of those

vital functions which characterise and compose the life-

history of each kind of animal.

The various vital functions of the body take place in the

intimate recesses of our frame quite unperceived, and in

a manner in no way directly controllable by us. Yet these

functions are so admirably interrelated that their common

result, under normal conditions, is continuous and prolonged

life.

Similarly, the intimate processes of repair after injury

can neither be perceived nor directly controlled, though their

outcome is the practical fulfilment of an indisputably

desirable end, and yet more is this evident as regards the

processes of embryonic development. In pure reflex action

we have a clear example of the close dependence of the

actions, and even the practically purposive actions, of animals,

on the structure and function of their nervous system ; while

in sensori-motor action, habit, instinct as fixed, and instinct

slightly modifiable by cognition, we meet with a gradual

transition from actions in which the will has no sway, and

which need not be even matters of cognition, to acts which

are results of a cognitive process, and are more or less

voluntary in character.

Instinct is a result a practically purposive and highly

intelligent result of an impulse which is blind and, so

to speak, mechanical. But we shall have, in the next

chapter, to revert to the question concerning the nature

are conditions indispensable for science, because they are

conditions indispensable for sensation, but also make it clear

what admirable results may proceed from causes seemingly

most inadequate.

The different " tissues " of our body are so combined as to

form efficient " organs," different sets of which are combined

into systems the activities of the tissues, organs, and

systems harmoniously resulting in the performance of those

vital functions which characterise and compose the life-

history of each kind of animal.

The various vital functions of the body take place in the

intimate recesses of our frame quite unperceived, and in

a manner in no way directly controllable by us. Yet these

functions are so admirably interrelated that their common

result, under normal conditions, is continuous and prolonged

life.

Similarly, the intimate processes of repair after injury

can neither be perceived nor directly controlled, though their

outcome is the practical fulfilment of an indisputably

desirable end, and yet more is this evident as regards the

processes of embryonic development. In pure reflex action

we have a clear example of the close dependence of the

actions, and even the practically purposive actions, of animals,

on the structure and function of their nervous system ; while

in sensori-motor action, habit, instinct as fixed, and instinct

slightly modifiable by cognition, we meet with a gradual

transition from actions in which the will has no sway, and

which need not be even matters of cognition, to acts which

are results of a cognitive process, and are more or less

voluntary in character.

Instinct is a result a practically purposive and highly

intelligent result of an impulse which is blind and, so

to speak, mechanical. But we shall have, in the next

chapter, to revert to the question concerning the nature