Ideas, thoughts of ends, are not spontaneously generated. There is no immaculate conception of meanings or purposes. Reason pure of all influence from prior habit is a fiction. But pure sensations out of which ideas can be framed apart from habit are equally fictitious. The sensations and ideas which are the "stuff" of thought and purpose are alike affected by habits manifested in the acts which give rise to sensations and meanings. The dependence of thought, or the more intellectual factor in our conceptions, upon prior experience is usually admitted. But those who attack the notion of thought pure from the influence of experience, usually identify experience with sensations impressed upon an empty mind. They therefore replace the theory of unmixed thoughts with that of pure unmixed sensations as the stuff of all conceptions, purposes and beliefs. But distinct and independent sensory qualities, far from being original elements, are the products of a highly skilled analysis which disposes of immense technical scientific resources. To be able to single out a definitive sensory element in any field is evidence of a high degree of previous training, that is, of well-formed habits. A moderate amount of observation of a child will suffice to reveal that even such gross discriminations as black, white, red, green, are the result of some years of active dealings with things in the course of which habits have been set up. It is not such a simple matter to have a clear-cut sensation. The latter is a sign of training, skill, habit. Admission that the idea of, say, standing erect is dependent upon sensory materials is, therefore equivalent to recognition that it is dependent upon the habitual attitudes which govern concrete sensory materials. The medium of habit filters all the material that reaches our perception and thought. The filter is not, however, chemically pure. It is a reagent which adds new qualities and rearranges what is received. Our ideas truly depend upon experience, but so do our sensations. And the experience upon which they both depend is the operation of habits--originally of instincts. Thus our purposes and commands regarding action (whether physical or moral) come to us through the refracting medium of bodily and moral habits. Inability to think aright is sufficiently striking to have caught the attention of moralists. But a false psychology has led them to interpret it as due to a necessary conflict of flesh and spirit, not as an indication that our ideas are as dependent, to say the least, upon our habits as are our acts upon our conscious thoughts and purposes.