“All other things being equal” is a clause in causal logic to rule out any other not explicitly acknowledged factors or variables from the reasoning. It is a construction to simplify the model of the world that is being built (and usually also: defended) by the person doing the reasoning. Asserting that “all other things are equal” is a basic operation of nearly all strict reasoning and model building.
But all other things just are not equal. Everything is in a constant flux, and the simple fact of observing any state of affairs will influence it. No model of reality can capture its full breadth and depth, no logic system can cope with the complexity that our senses can inhale, that our thinking can capture, that our creativity can express. If only momentarily so, but then that is basic to the structure of our being here.
Because all other things are not equal, we can differentiate between the real and the fake. Real is what takes into account the fleeting nature of our experiences and feelings and thoughts, fake is what tries to convince you that truth can be fixed, that meaning can be definitive, that feelings can be understood. Fake is what tries to be exhaustive. Anything that connects you to the endless is probably more real. The elegance of endlessness.
Is that Ockham whispering? If you have to assume that all other things are equal, you’d better beware. Do not assume. Just feel, just see, just hear, just smell, just taste. Then think, and write, and talk, and draw, and play, and dance.
And if ever you just have to assume that all other things are equal, then do not forget it is just that: an assumption. Which can be proven wrong. Guess what: I bet you that soon enough, it will.