It will be necessary here to say somewhat more than I have already said concerning inference. When I see an orange, that object is mentally constructed at the bidding of certain sight-sensations. All that is actually received is the stimulus of the retinal elements; the rest is suggested and supplied by the activity of the mind. It is sometimes said that this complementary part of the perception is inferred. So, too, when I hear a howl in the street which suggests the construct dog, it may be said that I infer the presence of the dog. And again, when the dog is perceived to be in pain, it may be said that this is an inference. Now, although the use of the word "inference" to denote the complementary part of a percept seems a little contrary to ordinary usage, still there are some advantages in so--with due qualification--employing it. But since, as it seems to me, the characteristic of the inference, if so we style it, in the formation of constructs by immediate association is its unconscious nature (i.e. unconscious as a process) we may perhaps best meet the case by speaking of these as unconscious inferences. When the inference is not immediate and unconscious, but involves a more individual conscious act of the mind in the perceptual sphere, we may speak of it as intelligent; and when the inference can only be reached by analysis and the use of concepts, we may call it rational. Defining, therefore, "inference" as the passing of the mind from something immediately given to something not given but suggested through association and experience, we have thus three stages of inference: (1) unconscious inference on immediate construction (perceptual); (2) intelligent inference, dealing with constructs and reconstructs (perceptual); and (3) rational inference, implying analysis and isolation (conceptual). Concerning unconscious inferences in animals, I need add nothing to that which I have already said concerning the process of construction. It is concerning the intelligent inferences[GU] of animals that I have now to speak.