INTRODUCTION

I would like to understand what the basic principles are that distinguish the vision of thought we have generated using the Strawson image of sameness marking from Frege's original vision of thoughts as exemplifying modes of presentation. The first conclusion I will reach is that, surprisingly, the way the Strawson markers mark identity plays no role in determining this difference. The interaction of Strawson's image of sameness marking with Frege's vision of modes of presentation yields strikingly unFregean results. Yet these results are not merely an artifact of the Strawson model. They follow given any model of sameness marking. Strawson's way of marking identity highlights a general feature implicitly present in all other models as well. It will take a while to argue for this conclusion. I will place particular emphasis on the equals marker, and on the image of thoughts as sentencelike, in which the equals-marker model is embedded. For initially it is quite unintuitive that this particular model is isomorphic to the Strawson model. Such is the hold that the mental sentence image of thought has on all of us, with its careful but, as I will argue, illusory distinction between duplicates markers and equals markers, that is, between graspings of necessary identity and contingent judgments of identity.

Further search is thus needed to understand the division between the vision of thought we have generated and Frege's original vision of thoughts as exemplifying modes of presentation. What exactly is the source of the difficulties we have encountered in trying to interpret what a mode of presentation might actually be in a thinking mind or brain?