Technically not a speech, but still an interesting listen. It’s very accessible and doesn’t get too technical.

A series of lectures by cybernetics researcher and Cybersyn developer Stafford Beer establishing the basis for cybernetics, in what looks a lot like a dialectical method. They make up around 3 hours of lectures, so you can listen to them as an audiobook with some capable app like Voice.

Transcripts here, with annotations and sketched diagrams: https://monoskop.org/images/e/e3/Beer_Stafford_Designing_Freedom.pdf