The transition from peace to predation therefore depends on the growth of technical knowledge and the use of tools.

A predatory culture is similarly impracticable in early times, until weapons have been developed to such a point as to make man a formidable animal.

The early development of tools and of weapons is of course the same fact seen from two different points of view.
The life of a given group would be characterised as peaceable so long as habitual recourse to combat has not brought the fight into the foreground in men's every day thoughts, as a dominant feature of the life of man.

A group may evidently attain such a predatory attitude with a greater or less degree of completeness, so that its scheme of life and canons of conduct may be controlled to a greater or less extent by the predatory animus.

The predatory phase of culture is therefore conceived to come on gradually, through a cumulative growth of predatory aptitudes habits, and traditions this growth being due to a change in the circumstances of the group's life, of such a kind as to develop and conserve those traits of human nature and those traditions and norms of conduct that make for a predatory rather than a peaceable life.
The evidence for the hypothesis that there has been such a peaceable stage of primitive culture is in great part drawn from psychology rather than from ethnology, and cannot be detailed here.