The evening before my talk at this conference on "Tarski and the Vienna Circle", Professor Hans Sluga of the University of California at Berkeley made the important point that we should discuss not only the historical past but also its impact — in other words, what happened (or did not happen) as a result of that past. I agree completely and I am happy to say that I intend to deal with exactly those issues. My title, "How the Unity of Science Saved Alfred Tarski", has two meanings: the first, quite literal. The second is less so and perhaps stretches the point, but it does bear on the question of "what happened."