A necessary incident to the power of government is the right, in the interest of the public, to control private property, even without the consent of the owner; and this is exercised within the scope of the police power, so that the public health, morals, and welfare will be protected. And as will appear in the discussion of taxation, the owner of private property may be compelled to contribute a portion of it for public purposes. (See below, § 70.) Furthermore, the public welfare or public necessity may even require the destruction of private property. Thus it appears that the owner of property exercises the privileges of ownership and possession subject to the paramount sovereign power of the state.

The owner of private property holds it also subject to a paramount right in the government to appropriate it to public uses without his consent. In this respect the individual interest should not be allowed to stand as against the sovereign will, exercised for a proper purpose. This paramount right of the government, whether federal or state, to appropriate private property to public use is called the power of eminent domain, which is not to be explained as resulting from any paramount title or reserved estate; nor as involving the theory that all property rights are derived from the government, subject to some restriction or condition that the government may retake the property for public purposes; but rather on the theory that the public interest is greater than any private interest, and that personal rights must be subjected, so far as necessary, to the public welfare. This is a condition essential to the existence of organized society, and comes about without constitutional grant. Various state constitutions and the federal constitution so far recognize the existence of this right on the part of these governments as to provide that it shall be exercised only on making compensation to the owner whose property is taken; and these are the only specific provisions with reference to the power of eminent domain. Before discussing the constitutional provisions and the various rules which result from their application, it is desirable to indicate more clearly the nature of the power as distinct from other governmental powers with reference to private property.

As already suggested, the power of eminent domain is distinguished from the police power in that the latter relates to restrictions on the use of private property in the interest of the public; while the power of eminent domain is exercised by the taking of private property and devoting it to public use. Thus in the exercise of the police power, the owner of intoxicating liquors, or one who has devoted his property to the business of manufacturing such liquors, may be so far restricted in the sale or manufacture as to greatly impair the value of the property thus owned; but so long as his property is not taken from him by the government to be used for some public purpose, he cannot say that it has been taken under the power of eminent domain. Again, as will be pointed out in the chapter relating to taxation (see below, ch. xii), while a property owner may be compelled to make contribution for the support of the government or for public purposes to which the government is justified in making appropriations, and his property may be seized and sold in order to compel the making of such contributions, yet the exercise of the power of taxation does not necessarily involve the taking of specific property for public use; and the power of taxation, therefore, while in some respects analogous to the power of eminent domain, especially as to the purposes for which it may be exercised, is nevertheless distinct from it. Nor does the destruction of private property by the government, or under its authority, involve the exercise of the power of eminent domain. For the purpose of stopping the progress of a fire in a city, the public authorities may destroy buildings, but it cannot properly be said that such destruction is an exercise of the power of eminent domain; it is simply the result of the discharge of a duty arising from necessity. In military operations, private property may be destroyed without the power of eminent domain being at all involved.