Science of Logic

Hegel's most demanding work, published in three parts between 1812 and 1816, with a revised first part completed shortly before his death in 1831. Despite the title it is not a manual of formal logic but an account of the basic categories of thought, which Hegel holds are also the basic forms of being. It begins with pure being, finds it indistinguishable from nothing, and shows that the truth of both is becoming. From there each category is shown to be one-sided and to pass into a fuller one. The Objective Logic contains the Doctrine of Being, covering quality, quantity and measure, and the Doctrine of Essence, covering reflection, appearance and actuality. The Subjective Logic, or Doctrine of the Concept, treats concept, judgement and syllogism, then mechanism, chemism and purpose, and ends with the absolute Idea, in which the method of the whole becomes its own content. It is the logical core of Hegel's system and the fullest statement of his dialectical method.

It is the boldest attempt to derive the basic concepts of thought without presuppositions, and it is the key to the dialectic later used, and reworked, by Marx and many others.