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We see trees, houses, fields, living beings in our own shape, and in shapes more or less analogous to our own. These are perpetually changing the mode of their existence relatively to us. To express the varieties of these modes, we say, WE MOVE, THEY MOVE; and as this motion is continual, though not uniform, we express our conception of the diversities of its course by--IT HAS BEEN, IT IS, IT SHALL BE. These diversities are events or objects, and are essential, considered relatively to human identity, for the existence of the human mind. For if the inequalities, produced by what has been termed the operations of the external universe, were levelled by the perception of our being, uniting and filling up their interstices, motion and mensuration, and time, and space; the elements of the human mind being thus abstracted, sensation and imagination cease. Mind cannot be considered pure.