自指包括否定性自指和肯定性自指。否定性自指往往导致自指悖论。自指悖论具有巨大的破坏性作用,其原因在于没有时间性,哥德尔不完备性定理和图灵对可判定性问题的证明便是其中的代表。分形几何、逻辑斯蒂方程、DNA转录和自复制程序则肯定了肯定性自指的建设性作用。肯定性自指将时间和生长因素引入到自指中,使之成为能够描述世界生成演化的生成逻辑。自指将时间引入到逻辑中来,具有重要的方法论意义。
Self- reference is made up of affirmative self- reference and negative self- reference.Negative self- reference always details paradox. Paradox of self- reference has great devastating effects on logic and mathematics which can be saw through Gdel's incompleteness theorem and the Halting Problem. Fractal Geometry,Logistic Equation,DNA transcription,and self- replicating program all present the constructive effects of affirmative self- reference. Affirmative self- reference takes time and generative factors into self- reference which turns it to be a kind of generative logic. It has an important methodological significance that takes time into self- reference.