First Property and Labor

One definition that Marx and Engels do offer is that of 'property': "the power of disposing of the labor-power of others", on the basis of which they equate Private Property and Division of Liberty. Furthermore, "first" property is that of wife and child for the husband. However, entailed in the definition is "the labor-power of others", e. g. of the wife, the products of which elsewhere in Marxism are conceived as the property of the producers. So, right in front of their methodically observing eyes is an example of Property that is presupposed by their definition of "first property", thereby undermining the soundness of the exposition in this section.