What now seems to me to be possible is that the sense datum which corresponds to a tree, which I am seeing, when I am a mile off, may not really be perceived to be smaller than the one, which corresponds to the same tree, when I see it from a distance of only a hundred yards, but that it is only perceived to seem smaller; that the sense datum which corresponds to a penny, which I am seeing obliquely, is not really perceived to be different in shape from that which corresponded to the penny, when I was straight in front of it, but is only perceived to seem different that all that is perceived is that the one seems elliptical and the other circular; that the sense datum presented to me when I have the blue spectacles on is not perceived to be different in colour from the one presented to me when I have not, but only to seem so; and finally that the sense datum presented when I touch this finger is not perceived to be different in any way from that presented to me when I see it, but only to seem so that I do not perceive the one to be coloured and the other not to be so, but only that the one seems coloured and the other not.