Every being with an other marks a real difference. However much you might be able to reduce the inert, nonliving or unresponding object to an aspect of yourself, a construction or a field constituted by your world-making imagination, you cannot do so with another human subjectivity, even if their equivalent subjecthood can only be understood as resulting from an act of faith. In the human context framing speculation you are necessarily accompanied by independent and equivalent subjectivities. Another self is not a phenomenon, the constituent phenomena do not sum to a locatable, if admittedly more complex, phenomenon. There is in them a spontaneity, a source; they too give rise to phenomena, to a world - one that is parallel and different from yours - a world you are compelled to acknowledge, even at the price of absolute difference. The ineluctable modality of the other.