Legislative classification by industry

The legislature is not debarred from classifying according to general considerations and with regard to prevailing conditions; otherwise, there could be no legislative power to classify. For it is always possible by analysis to discover inequalities as to some persons or things embraced within any specified class. A classification based simply on a general description of work would almost certainly bring within the class a host of individual instances exhibiting very wide differences; it is impossible to deny to the legislature the authority to take account of these differences, and to do this according to practical groupings in which, while certain individual distinctions may still exist, the group selected will, as a whole, fairly present a class in itself.