All perceptions are thoughts. One might claim, on the other hand, that all thoughts are not perceptions. One might define "perceiving" as a special kind of thought, as real objective thought in distinction from supposing, believing, or imagining. But it cannot be denied that all thoughts have a common nature, in spite of their many differences. Thought is treated in the court of the faculty of thought like all other things, it is made uniform. No matter how different the thoughts I had yesterday may be from those I have to-day, no matter how much the thoughts of different human beings may vary at different times, no matter how clearly we may distinguish between such thoughts as those expressed by the terms idea, conception, judgment, conclusion, impression, etc., they each and all possess the same common and universal nature, because all of them are manifestations of mind. It follows, then, that the difference between true and erroneous thoughts, between understanding and misunderstanding, like all other differences, is only relative. A thought "in itself" is neither false nor true, it is either of these only in relation to some other object. Thoughts, conceptions, theories, natures, truths, all have this in common that they belong to some object. We have seen that any object is a part of the multiplicity of sense perceptions in the world outside of our brains. After as much of the universal being as constitutes the object which is to be understood has been defined by some customary term of language, truth is to be found in the discovery of the general nature of this perceptible part of being. The perceptible parts of being which constitute the things of this world have not only a semblance and manifestation, but also a true nature which is given by means of their manifestation. The nature of things is as infinite in number as the world of sense perceptions is infinitely divisible in space and time. Every part of any phenomenon has its own nature, every special phenomenon has its general truth. A phenomenon is perceived in touch with the senses, while the true or essential nature of things is perceived in contact with our faculty of thought. In this way we find ourselves face to face with the necessity of speaking here, where the nature of things is up for discussion, simultaneously of the faculty of thought, and on the other hand of dealing with the nature of things when the faculty of thought is our main subject.