History, as much as logic, has shaped the English real property law of today. The richness of that history is one of its strengths, but is also a potential source of weakness, as where the boundaries between similar, but distinct rights are neither theoretically nor logically distinguished. Whilst this may often not be of practical concern, none the less a lack of logic may lead to inconsistency or uncertainty in the law (or indeed both). Particularly is this so where social pressures require protection for new situations, as for example where a flat owner requires the certainty that his right to park his car is a proprietary right.

That provides one justification for seeking a strong and consistent theoretical framework. Another is that as we integrate more closely with our European partners, we may be compelled to accept into our thinking concepts which are at present alien to us.

The word ‘estoppel’ had its origins in the old French word ‘estoup’, meaning plug or stopper. The principle of estoppel by representation of fact operates in a manner which is consistent with those origins. Where a representation of fact is relied upon by a representee, the effect of the estoppel is to stop up the mouth of the representor, and prevent him or her from asserting facts contrary to his or her own representation. The rights of the parties are then determined by reference to the represented or assumed state of affairs. An estoppel by representation of fact can be used defensively, where an action which would otherwise be available to the plaintiff is not available on the assumed state of affairs. It can also be used aggressively, to establish a state of affairs in which a cause of action exists, where that cause of action would not be available on the true state of affairs.

Legal doctrine has two aims: describing and systematising the law. The description of currently valid law within a given legal system is the most visible and, from a quantitative point of view, the most important task for legal doctrine. From a qualitative point of view, however, systematisation of the law is by far its most important task. Systematisation is the construction of a conceptual framework of the law, which is a necessary basis for any legal rule and for any legal reasoning. Systematisation presupposes a description of the rules, principles, concepts, etc, which are to be systematised. But description of the rules is impossible without the conceptual framework that the systematisation of the law offers. Even the law itself is based on this conceptual framework. Codifications, such as the Code Napoléon or the German Bürgerliches Gesetzbuch, were made possible because of the centuries-long preparatory work of legal doctrine.

Successful law reform campaigns leave behind a rich history; a story of engagement between activists seeking legal change, opponents who attempt to maintain the status quo, legislators, and the judiciary. The repeal of the provisions of the Tasmanian Criminal Code which prohibited certain private, consensual sexual relations between adults, and which were aimed primarily at male samesex sexual acts, by the state legislature in May 1997, signaled the end of a particularly arduous campaign which lasted several years. What makes this struggle worthy of academic treatment, first, is the simple fact that the gay activist campaign was waged over a plurality of legal and political sites at the state, national, and international levels.

All the efforts of human reason tend to the elimination of [the other]. The other does not exist: such is rational faith, the incurable belief of human reason. Identity = reality, as if, in the end, everything must absolutely and necessarily be one and the same. But, the other refuses to disappear: it subsists, it persists; it is the hard bone on which reason breaks its teeth. [There is] what might be called the incurable otherness from which oneness must always suffer.

Ownership of the family home is usually not disputed until either the relationship between the spouses or cohabitants breakdown or there is a competing claim over the property by a third party. In such circumstances, determination of ownership rights becomes imperative. The Matrimonial Causes Act 1973 gives the courts adjustive powers to deal with disputes between spouses on the breakdown of the marriage. Notwithstanding this, there may be circumstances where it will be necessary or desirable to determine property rights between spouses. Furthermore, the adjustive powers of the courts are not applicable to cohabitants. Thus, in the absence of legal co-ownership in the family home, cohabitants and spouses who cannot rely on the 1973 Act will have to establish an equitable interest in the property. The analyses relied on are primarily based on property law and trusts principles and, more particularly, imputed trusts and proprietary estoppel. Under trusts principles, imputed trusts are usually taken to refer to resulting and constructive trusts.