This article argues that the express trust should be understood as a species of obligation rather than as a means of organising the ownership of property. Two propositions seem fundamental to the traditional understanding of the trust as an aspect of property law. Firstly, in the nature of the trust, there must be a separation of legal and beneficial ownership. Secondly, there must be trust property. Neither is necessarily true. With many discretionary trusts and other recognised types of express trust it is impossible to locate the beneficial estate. Furthermore, the requirement for there to be trust property is, on closer analysis, a requirement of certainty of obligation in relation to specific subject-matter within which the trust property can be located.
The article explores the implications of understanding the trust as a species of obligation. It allows all express trusts, including charitable trusts, to be explained as resting on the same fundamental concepts. The trust in the common law world may still be distinguished from contract and from the civil law forms of the trust. This new conceptualisation also illuminates what is the irreducible core content of the trust. The article concludes with a new definition of the express trust.