'Fault lines' in certainty of object for private trusts: 'none the worse for it'?

It is well established that the validity of trusts is grounded in, amongst other things, certainty of object. Courts have developed rules, which function in a binary fashion as 'fault lines', directed to distinguishing objects that are certain from those that are not. At the same time, instances arise that test the boundaries of these lines. This article probes such instances, on the way to revealing that the concept of certainty of object may be more fluid, and indeed less precise, than may have been imagined. And it ultimately raises the question whether the law should be any the worse for this.