ABSTRACT
In a given sense-history there is one and only one time-direction. This is because the simultaneity or successiveness of sensa in the same sense-history is actually sensed, and we have therefore no choice as to which we shall group together as simultaneous, and which we shall group apart as successive. The succes sive slabs of the sense-history are given to us in the form of sense-fields, and the only possible time-direction is that of their common normal. The only choice allowed to us is that we could take any straight line in the sensehistory, parallel to the time-direction, as a permissible time-axis, assuming that the geo-chronometry of the sense-history is Euclidean.