Do we need a « common ground » in order to communicate with each other effectively or enjoyably? Interpreted in terms of the classical image of thought, the requirement of a common ground bespeaks fidelity to a principle of convergence and of commensurability. Deleuze has taught us to that another image of thought is possible, where engagement in a « common cause » instigates changing alliances, collaborations, and friendships.
I am committed to open dialogue and to a democratic pluralism of thought, I have no desire for foundations (« ground ») nor do I valorise the commensurable (« common ») over incommensurability and divergence. I have no need of commonality to engage in a democratic exchange. Understood in classical terms « common ground » is, to say the least, undesirable – a form of determination of dialogue by a transcendence.
But this expression can also be understood in a freer, more open (more « quantum ») way. « Common ground » in this sense is more an event, re-invented each time, never assured, a provisional passage. This is why I speak so much of plurality, superposition, porosity, and quantum tunneling, as I do in many of my articles in this blog and in the discussions that I participate in here and elsewhere. Immanence is not just an abstract concept, a counter in an academic game, it can be seen very concretely in how you write and how you talk to others.
Note: I am indebted to a discussion with Martin E. Rosenberg for prompting me to clarify this point