In this sphere of Relativity the terms expressive of things come in pairs: such as Same and Different, Like and Unlike: True Being and Show or Semblance: Cause and Effect: Substance and Accident: Matter and Form: and the like. If we compare mere Being to the cell in its simple state, we may say that in the second sphere of Logic a nucleus has been formed,--that a distinction has sprung up between two elements, which are still in closest interconnexion. We have penetrated behind the seeming simplicity of the surface: and in fact discovered it to be mere seeming in the light of the substratum, cause, or essence, upon which it is now reflected. In immediate Being one category, or specificate, or dimension of thought passes over into another, and then disappears: but in mediated Being one category has a meaning only by its relation to another,--only by its reflection on another,--only by the light which another casts upon it. Thus a cause has no meaning except in connexion with its effect: a force implies or postulates an exertion of that force: an essence is constituted by the existence which issues from it. Instead of 'is,' therefore, which denotes resting-upon-self, or connexion-with-self, the verb of the second sphere is 'has,' denoting reference, or connexion-with-something-else: e.g. the cause _has_ an effect: the thing _has_ properties. Instead of numerals, come the prepositions and pronouns of relation, such as which, same, like, as, by, because. The only conjunction in the first stage or Being was 'And,'--mere juxtaposition; and even that conjunction was perhaps premature, and due to reflective thought, going beyond what was immediately before it, and tracing out connexions with other things. The first stage, as we have seen, treated of the terms of natural thought present in the action of the senses: the second stage--that of Essential Being--deals with scientific, reflective, or mediate thought. What, why, are the questions: comparison and connexion the methods: the establishment of relations of similarity, causation, and co-existence, the purpose in this range of logical method. Its categories are those most familiar to science in its reflective and comparative stage. It is the peculiar home of what are known as Metaphysical subtleties. The natural but delusive tendency of reasoning is to throw the emphasis on one side of the relation, and to regard the other as accessary and secondary. Contrasts between _essentia_ and _existentia: substantia_ and _modi_: cause and effect: real and apparent: constantly occur.