Equity is a concept of
rights distinct from legal (that is,
common law) rights; it is (or, at least, it originated as) "the body of principles constituting what is fair and right (
natural law)". It was "the system of law or body of principles originating in the
English Court of Chancery and superseding the common and
statute law (together called 'law' in the narrower sense) when the two conflict". • Equitable interest is a right against a right, rather than right against a thing or right against a person. • Whenever a party B has a right against a right of another A, B's right is
prima facie binding on anyone who acquires a right that derives from A's right. • B will acquire such a persistent right whenever A is under a duty to hold a specific claim-right or power, in a particular way, for B. The rights and
obligations of the beneficiary, trustee, third parties contracting with the trust and potentially of other parties (such as the settlor of the trust or, if the trust provides for such, a protector or enforcer of the trust) depend on the terms of the trust deed. Trust law includes both mandatory law (that is, law which cannot be excluded, such as the irreducible core,
information rights and the supervisory
jurisdiction of the court) and
default law (that is, law which can be excluded by express provision in the trust deed). The trust deed, therefore, has a significant role to play in determining the rights and obligations of the parties in that default law (such as fiduciary obligations and rights of recourse against non-entitled third parties) may be excluded or modified by the trust deed. In
DKLR Holding Co (No 2) Pty Ltd v Commissioner of Stamp Duties (NSW), the
High Court of Australia held that if a person has an equitable interest in property, this implies that some other person has the legal interest in that property. If one person has both the legal and equitable interest in the relevant property, he or she has no 'equitable interest' in that property as such.
Aickin J said "If one person has both the legal estate and the entire beneficial interest in the land he holds an entire and unqualified legal interest and not two separate interests, one legal and the other equitable". As stated by Brennan J held that "[an] equitable interest is not carved out of a legal estate but impressed upon it". Mere equity, for example, may arise when one party has been unjustly disadvantaged by the unconscionable behaviour of another. Importantly, however, a 'mere equity' will not prevail over an actual bona fide equitable interest – such as an equitable charge. ==Land law==