different universe, a universe that is, for us, quite unimaginable. And the universe that the mind has selected and constructed from the world of point-events does not in the least depend on what the point-events _are_. All that is necessary is that a certain minimum amount of structure should be attributed to the world of point-events. It is from the relations between the point-events, quite independent of their substance, that the mind has created the material universe and its laws. These laws, it must be emphasized, are _necessary_ consequences of the mind’s selective action. They are necessary in the same sense that the sum of the three interior angles of a Euclidean triangle must be two right angles. Of the underlying reality deduced by physics we can say almost nothing. It may be what Newton called the “sensorium” of God, and the point-events may be his thoughts. They do not succeed one another in time for, at this stage of analysis, space and time are “merged in one”. This perfectly gratuitous hypothesis may appeal to some mystics, for our thoughts, considered as belonging to the world of point-events, would be part of the thoughts of God. It would be indeed true that in him we lived and moved and had our being. We see, then, the limitations of physics. All that depends on the _structure_ of reality belongs to physics, including other universes than ours. All that depends upon the _substance_ of reality for ever lies outside physics. As to the actual universe we live in, why we should regard it as actual is a problem for psychology. The difference between the actual and the non-actual is a distinction conferred by our minds. It is very probable that the whole movement of the universe in time is also contributed by our minds. It seems to be true that events do not take place――we come across them. Why we do not know the future is again a question of psychology. Ignorance of the future, like the existence of the material universe, is a clue to the constitution of our minds. This has a bearing on the question of “purpose” in the universe. The conception of purpose seems to suppose a process in time, and therefore may be a totally irrelevant idea when applied to reality.