Aufheben or Aufhebung is a German word with several seemingly contradictory meanings, including "to lift up", "to abolish", "cancel" or "suspend", or "to sublate". The term has also been defined as "abolish", "preserve", and "transcend". In philosophy, aufheben is used by Hegel to explain what happens when a thesis and antithesis interact, and in this sense is translated mainly as "sublate".
In Hegel, the term Aufhebung has the apparently contradictory implications of both preserving and changing, and eventually advancement (the German verb aufheben means "to cancel", "to keep" and "to pick up"). The tension between these senses suits what Hegel is trying to talk about. In sublation, a term or concept is both preserved and changed through its dialectical interplay with another term or concept. Sublation is the motor by which the dialectic functions.
Sublation can be seen at work at the most basic level of Hegel's system of logic. The two concepts Being and Nothing are each both preserved and changed through sublation in the concept Becoming. Similarly, determinateness, or quality, and magnitude, or quantity, are each both preserved and sublated in the concept measure.
Hegel's philosophy of history stresses the importance of negative (the antithesis) in history—negative includes wars, etc., but not only. His conception of historical progress follows a dialectic spiral, in which the thesis is opposed by the antithesis, itself sublated by the synthesis. Hegel stated that Aufheben is uniquely exempt from the historical process in that it is supposed to be true for all time and never changes or develops further as in das absolute Wissen ("absolute knowledge"). The synthesis both abolishes and preserves the thesis and the antithesis, an apparent contradiction which leads to difficulties in interpreting this concept (and to translate Aufheben). In Hegel's logic, self-contradiction is legitimate and necessary.
For Hegel, history (like logic) proceeds in every small way through sublation. For example, the Oriental, Greek and Roman Empires (in which the individual is ignored or annihilated, then recognized, and finally suppressed by the States) are preserved and destroyed in the First French Empire, which, for Hegel, placed the individual in harmony with the State.
Hegel approached the history of philosophy in the same way, arguing that important philosophical ideas of the past are not rejected but rather preserved and changed as philosophy develops.
In Hegel's view, one can always find another thing in reflective philosophy upon which some "absolute" ground relies. With Fichte's ultimate ground, the "I" or "ego", for example, one can immediately see the reliance upon the "non-I", which allows Fichte to distinguish what he means by the "I". Reflection is circular, as Fichte unapologetically acknowledged.
Instead, Hegel calls on speculative thought: two contradictory elements are held together, uplifted and sublated without completely destroying one another. Speculative thought seeks to avoid the idealism inherent in reflective thought and allows one to think in concrete terms about how things work, both in the present, real world and in history.
Marx identifies sublation as the manner in which material, historical conditions develop. This is in stark contrast to the philosophical idealism of Hegel, for whom sublation reflects the agency of a specific Geist – a concept that has often been translated as "mind" or "spirit".