PHYSICAL ANTECEDENTS OF SCIENCE 127

If an act performed only once had not in it some power of

generating a habit, then a thousand repetitions of that act

would not generate it. Habit is the determination in one

direction of a previously vague tendency to action. We

possess a natural inclination to activity. Action is not only

natural to us, it is a positive want. Our powers and energies

also tend to increase with exercise and action (up to a certain

limit), while they diminish and finally perish through a too

long repose. Thus a power of generating " habit " lies hid

in all, and in the very first of those actions which facilitate

and increase the general activity and power of our body

and facilitate and increase the exercise of that power in

definite modes and directions.

This tendency to bodily and mental activity, which under-

lies our acquisition of " habits," is closely allied to that

special form of action which we have above spoken of as

" instinctive action." Instinct, as a feeling, will concern us

in the next chapter, but its physiological and physical

aspects must be noticed here. Instinctive movements differ

from reflex actions in that they are not merely respon-

sive to a stimulus felt, but respond to that stimulus in

such a manner as to serve a future unforeseen purpose.

Such an action is that of the infant, which, in response to

the feeling produced on its lips by contact with the breast,

first sucks the nipple and then swallows the thence extracted

nutriment with which its mouth becomes filled. It is an action

necessary for the nutrition of the infant, and one performed

very soon after birth, when there has been no lapse of time

wherein it could have learnt to perform that action. It is

also an action which is definite and precise, and one per-

formed in a similar manner by all infants, though it is

effected by a very complex mechanism, and is performed

at once, prior to all experience. But not only sucking and

deglutition, but also the movements by which the products

If an act performed only once had not in it some power of

generating a habit, then a thousand repetitions of that act

would not generate it. Habit is the determination in one

direction of a previously vague tendency to action. We

possess a natural inclination to activity. Action is not only

natural to us, it is a positive want. Our powers and energies

also tend to increase with exercise and action (up to a certain

limit), while they diminish and finally perish through a too

long repose. Thus a power of generating " habit " lies hid

in all, and in the very first of those actions which facilitate

and increase the general activity and power of our body

and facilitate and increase the exercise of that power in

definite modes and directions.

This tendency to bodily and mental activity, which under-

lies our acquisition of " habits," is closely allied to that

special form of action which we have above spoken of as

" instinctive action." Instinct, as a feeling, will concern us

in the next chapter, but its physiological and physical

aspects must be noticed here. Instinctive movements differ

from reflex actions in that they are not merely respon-

sive to a stimulus felt, but respond to that stimulus in

such a manner as to serve a future unforeseen purpose.

Such an action is that of the infant, which, in response to

the feeling produced on its lips by contact with the breast,

first sucks the nipple and then swallows the thence extracted

nutriment with which its mouth becomes filled. It is an action

necessary for the nutrition of the infant, and one performed

very soon after birth, when there has been no lapse of time

wherein it could have learnt to perform that action. It is

also an action which is definite and precise, and one per-

formed in a similar manner by all infants, though it is

effected by a very complex mechanism, and is performed

at once, prior to all experience. But not only sucking and

deglutition, but also the movements by which the products