Hans Herzberger's 1973 essay ‘Ordinal Preference and Rational Choice’ is a classic milestone in the erosion of the idea that rational agents are maximizers of utility. By the time Herzberger wrote, many authors had replaced this claim with the thesis that rational agents are maximizers of preference. That is to say, it was assumed that at the moment of choice a rational agent has a weak ordering representing his or her preferences among the options available to the agent for choice and that the rational agent restricts choice to one of the optimal options. Such an option is an available option judged at least as good as imy other.

It is often said that an argument is valid if and only if it is impossible for its premises to be jointly true and its conclusion false. Usually there is little harm in saying this but it places the concept of truth at the very heart of logic and, given how complex and obscure that concept is, one might wonder if trouble arises from this.

It does - in at least two contexts. One of these was explored in the first half of the fourteenth century by Jean Buridan and by the mysterious figure known as the Pseudo-Scotus of the Questions on the Prior Analytics printed in the edition of Scotus's works edited by Luke Wadding. Buridan thought that the bearers of truth were particular sentence-tokens; he thought of ttuth as a property of those tokens and he thought that nothing had properties unless it existed.

Setting out to understand Frege, the scholar confronts a roadblock at the outset: We just have little to go on. Much of the unpublished work and correspondence is lost, probably forever. Even the most basic task of imagining Frege's intellectual life is a challenge. The people he studied with and those he spent daily time with are little known to historians of philosophy and logic. To be sure, this makes it hard to answer broad questions like: ‘Who influenced Frege?’ But the information vacuum also creates local problems of textual interpretation. Say we encounter a sentence that may be read as alluding to a scientific dispute. Should it be read that way? To answer, we'd need to address prior questions. Is it reasonable to think Frege would be familiar with the issue? Deep or superficial familiarity? Would he expect his readers to catch the allusion? Can he be expected to anticipate certain objections? Can people he knows be expected to press those objections? A battery of such questions arise, demanding a richer understanding of Frege's environment.

Hans Herzberger as a philosopher and logician has shown deep interest both in the philosophy of Gottlob Frege, and in the topic of the inexpressible and the ineffable. In the fall of 1982, he taught at the University of Toronto, together with André Gombay, a course on Frege's metaphysics, philosophy of language, and foundations of arithmetic. Again, in the fall of 1986, he taught a seminar on the philosophy of language that dealt with ‘the limits of discursive symbolism in several domains of human experience.’ The course description continues by saying: ‘Special attention will be given to the paradoxes underlying various doctrines of the inexpressible and the tensions inherent in those paradoxes. Some doctrines of semantic, ethical and religious mysticism will be critically examined.'

Amidst many discussions on super-valuational algebras and their philosophical applications - on which I was writing my dissertation - Hans and I once paused to ponder the mystical experience of the square. I mean A Square, the hero of Flatland. I mean that perfectly two-dimensional being, with no depth whatsoever, citizen of an equally two-dimensional depthless world, who one day had the good fortune of receiving a visit from a Sphere. What's more, he had the fortune of being able to visit, albeit briefly, the undreamt-of three-dimensional world his guest came from - which is to say, our threedimensional world. He visited and experienced our world before falling back for all eternity into the total flatness of his: Flatland, the plane world, the world with no aboves and no belows, the world in which cars and airplanes alike, so to speak, belong to the same category, and everything, literally everything, is reduced to fragile shadows on an enormous and eternally illuminated floor.

Here is Frege in Foundations of Arithmetic, §64: