This is totally orthogonal to your original claim that systems thinkers are "liberal" philosophers but OK.

McCulloch and Pitts, early cyberneticians literally invented neural networks. See the wikipedia page on neural nets.

Another really simple one: Law of Requisite Variety. If that's too simple, I'd encourage you to bear in mind that Norbert Wiener, beyond his direct contributions to mathematics in the form of signal processing filters, is also responsible for the view of control as communication, which motivates much of the approach to control and stability in digital systems.