In a fruiterer's shop on the opposite side of a street I see an orange. That is to say, certain cones of the retina of my eye are stimulated by light-waves of a yellow quality, and at the bidding of these stimuli I construct the object which I call an orange. That object is distant, roundish, yellow, resisting and yet somewhat soft, with a peculiar smell, and possessed of a taste of its own. Now, it is obvious that I cannot see all these qualities of the orange, as we call them. I construct the object on reception of certain light-waves which are focussed on the retina of my eye. If I go to the orange, however, I can test the correctness of my construct by the senses of touch, smell, and taste. But what led me to construct an object with these qualities? Experience has taught me that these qualities are grouped together in special ways in an orange. I constructed that particular object through what is termed the principle of association. I have learnt that these qualities are grouped together in certain relations to each other, and when I actually receive sight-stimuli of a certain quality, grouped in certain ways, they immediately call up the memories of the associated qualities. That which is actually received is a mere suggestion, the rest is suggested in memory through association. The object might be suggested through other senses. I come into a dining-room after dessert, and the object is suggested through smell. Or my little son says, "Open your mouth and shut your eyes, and see what the fairies will send you;" and an orange is suggested by taste. In all these cases the object is constructed at the bidding of certain sensations, which suggest to my mind the associated qualities. The object is a _construct_. And here let us notice that we ascribe the form, the resistance, the taste, the smell, to the object. We do not say or think, "Sight-sensations inform me that there is something which I call an orange, and which is capable of exciting in me sensations of touch, taste, and smell;" but we say, "There is an orange, which _has_ such and such a taste, smell, and feel." In other words, we refer these sensations, related in certain ways, outwards to the object, and name them qualities of the object that we see. But remember, that we do not necessarily or normally say or think anything about it. We just inevitably construct the object, what we build in to the construct depending upon association through experience.