Introduction

In April 1994 an international workshop was held in Tel Aviv and Jerusalem on "Images of Knowledge, Two-Tier Thinking, and Higher Education."These themes stand as a clear marker for their author. They signal his scholarship and bear witness to his continuing quest for knowledge that refuses to be confined within academic boundaries. The workshop was intended to bring together scholars and friends of Yehuda Elkana in order to celebrate a committed intellectual, a historian of science with wide-ranging interests, an excellent teacher, and a genuine humanist. Let me also mention that Yehuda was the initiator of SiC and one of its editors for many years. His personal and political life as well as his work can perhaps best be summarized by the notion of epic theater that he discovered in Benjamin and Brecht: "It can happen this way, but it can also happen quite a different way." It stands for shunning the seemingly inevitable course of history and for refusing to believe in the One and only One — whether this is One Eternal Truth, buttressed by seemingly unchangeable metamathematical concepts like proof; or the inevitable development of One Science — namely, our science — regardless of what other cultures have produced; or the ways in which we think our history — namely, in terms of epochs, paradigms, and other grand narratives; or the still widespread context-free search for universals and universalistic theories. The gate has thus been pushed wide open to place into their cultural context and into the historical flux of development all our guiding concepts and the knowledge with which we seek to obtain a better grasp of the world around us. But at the same time there is an irrefutable and courageously steadfast element of realism in the notion of epic theater as the mirror of our experience in the way we live our history. The courage lies in accepting what cannot be changed, while knowing and actively searching to change it. Yehuda Elkana's ability to straddle the two sides of what many take to be intolerable contradictions has led him to articulate the notion of "two-tier thinking." Realism and relativism, he maintains, are not mutually exclusive; they are held simultaneously by most of us on most issues. We select a framework relativistically in full consciousness of the fact that we cannot prove the correctness of the choice and realize that we could have made a different choice. Yet once our choice is made, we relate to the selected framework, we think of it, realistically. This refusal to choose between realism and relativism and the claim that we adopt both views is characteristic of Yehuda's way of thinking. The two papers in this volume that address the issue directly, those by Gideon Freudenthal and Adi Ophir, reach their verdict independently of each other: both claim that two-tier thinking is not