We can speculate that Gottfried Wilhelm von Leibniz [L1 ] (1646-1716), who largely invented our modern notions of binary arithmetic, feedback, and symbolic computation, would have liked Tcl if only in appreciation for tclsh's provision of an interactive propositional calculator [L2 ], as well as the language's Unicode-savvy adeptness with human scripts.
Leibniz' current reputation in the Anglo world is less than he deserves, testimony to Newton's powers of vilification.
[Maybe mention the connection with monads.]