All over the world we find that industrial wage-labour requires protection of various kinds, differing, that is, not only in its nature but in the course and method of its application. On account of these very differences, before we can go a step further in the elucidation of the Theory and Policy of Labour Protection, we must divide industrial wage-labour into classes, according to the kind of protection which is needed, and the manner in which such protection is applied by protective legislation. It will now be our task, therefore, to classify them, and to be sure that we arrive at a clear idea of the various classes into which they fall for the purposes of protective legislation, some of which may not perhaps be readily apparent at first sight. The varieties of protection needed by industrial wage-labour arise, partly out of dangers peculiar to the particular occupation in which the wage-labourer is employed, and partly out of the personal characteristics and position of the labourer to be protected; _i.e._ they are partly exterior and partly personal. When the protection is against exterior dangers we have to consider sometimes the great diversity of conditions in the different occupations and industries, and sometimes the special manner in which workmen may be affected within the limits of a single occupation peculiar to some special branch of industry. When the protection is of the kind which I have called personal, the need for it arises partly out of the special dangers to which the protected individual is liable _outside_ the actual limits of his business, partly out of the special dangers attached to his position _in_ that business. Hence results the following classification of industrial wage-labour, according to the kind of protection required:-- I. Labourers requiring protection against _exterior_ dangers: _a._ According to the kinds of occupation: 1. Having reference to the different branches of industry: Wage-labour in mining, manufacture, trade, traffic and transport, and in service of all kinds. 2. Having reference to the special dangers of employment within any particular branch of industry: dangerous--non-dangerous work. _b._ According to type of business: 1. Having reference to the position or personality of the employer: Wage-labour under private employers--wage-labour under government. 2. Having reference to the choice of the labourers by the employer, and the nature of their mutual relations. Factory-labour, Quasi-factory labour (especially labour in workshops of a similar nature to factories), other kinds of workshop labour, Household industries (home-labour), Family labour. II. Labourers requiring protection against _personal_ dangers: _a._ Having reference to the common need of protection as men and citizens. 1. Adult--juvenile workers; 2. Male--female workers;