The contention that it is open to the landowner to invalidate the purported acquisition by proof that a purpose or intent of putting the land to a use falling within the legislative powers of the Commonwealth did not exist in the Governor-General rests upon a construction given to s. 51 (xxxi.). It is said that the power to make laws with respect to the acquisition of property on just terms for any purpose in respect to which the Parliament has power to make laws is a power with respect to a composite conception in which the notion of the acquisition of property is one element, the provision of just terms another element, and the independent existence of an actual intention of using the land for a purpose in respect to which the Parliament has power to make laws a third element. The argument is that unless the condition expressed in the word "for" is satisfied in the case of any given acquisition it cannot be authorized by a law made under s. 51 (xxxi.) and that the condition expressed by the word "for" cannot be satisfied unless as a matter of fact there exists, independently of any formal declaration, an intention to use the property for a purpose of the required character. It will be seen that the word "for" is construed as requiring an actual existing intention in the acquiring authority, which under the Lands Acquisition Act is the Governor-General in Council. The words "any purpose in respect to which the Parliament has power to make laws" were equivalent, so it was said, to "any use in respect to which the Parliament has power to make laws". It may be doubted whether the substitution of the word "use" for the word "purpose" makes the meaning any clearer. It seems to be plain enough that the Constitution, in using the word "purpose", is speaking of the object for which the land is needed. The word itself does not refer to any power or powers defined in the various paragraphs of ss. 51 or 52 of the Constitution or elsewhere conferred; it is referring to the object for which the land is acquired. That object, however, must be one falling within the Commonwealth's power to make laws. It does not matter, however, from which of the paragraphs the power to make a law covering that object is derived. No doubt for practical purposes the word "use" would have the same meaning as the word "purpose" in par. (xxxi.) of s. 51, but of course "use" must be given a very wide meaning.