Dynamic dispatch just means you're calling a function that happens to call another function. You're still calling a function. I don't think "You don't know the

Dynamic dispatch just means you're calling a function that happens to call another function. You're still calling a function. I don't think "You don't know the implementation" implies you're not calling a function - otherwise we'd have to say that when you use a shared library like OpenSSL, you don't "call" SSL_CTX_init(), you pass a message to the OpenSSL library, which might be 1.1.0 or 1.1.1 or even BoringSSL. But nobody would say that - it's obviously a function call. (I suppose you could defensibly argue that a system call is message passing, at least on some OSes, but that's about it.)