Sha and the Question of a Semitic Source

The similarity between the Slavonic letter for sh and the Hebrew letter shin is the oldest and most frequently cited piece of evidence for a Semitic component in the design of the Slavonic alphabets. Both letters write the same sound, both are three-pronged in their common forms, and the correspondence is close enough that it has been noticed independently by many readers.

What it proves is another matter. Two arguments run against taking it as a settled derivation. The first is that visual resemblance between letters of unrelated scripts is common and easy to over-read, and palaeography has a long record of resemblances that dissolved when the intermediate forms were examined. The second is that the same Slavonic letter has been explained in other ways, as a form composed for the purpose or as an adaptation of a Greek cursive shape, and those explanations account for the same evidence.

What is not in doubt is that a Byzantine scholar of Constantine's education could have known a Semitic alphabet. The sources describe him as a learned man sent on missions to peoples outside the Greek world before the Moravian journey, and knowledge of Hebrew would not be surprising in such a figure. That establishes opportunity and not much else. The atlas records the link as debated, names the camps and leaves the question where the evidence leaves it.