In his 2014 paper entitled “Reason, Rationality and Fiduciary Duty”, Lydenberg ventures into the field of the moral and political philosophy dealing with distributive justice in search of fresh perspectives on fiduciary duty. Simply by doing this, Lydenberg makes the very important contribution of drawing a little more attention to the potential that this huge field of study might have in relation to understanding socially responsible investment. There are however difficulties with Lydenberg’s paper. I describe three in particular that I (...) believe warrant critical attention. The first emerges out of Lydenberg’s treatment of the central concepts of reasonableness and rationality. The second lies in his apparent suggestion that at some earlier time fiduciary duty was somehow more generally other-considering than it is today. And finally, the third is associated with the place that impartiality occupies in Lydenberg’s storyline, and the implications of this in terms of his call for a reconciliation between reasonableness and rationality. This critical scrutiny clarifies theoretical and practical implications of the transition Lydenberg is suggesting. In doing this, it makes the realization that what Lydenberg is attempting is more than likely nothing short of resolving “The fundamental problem of ethics and politics” in the specific context of fiduciary action. (shrink)