Professor Li Candong puts forward the"five differentiation"thinking in TCM:symptom differentiation,syndrome differentiation,disease differentiation,person differentiation and mechanism differentiation.This article discussed the thinking and method of application of classical prescriptions based on the mode of"five differentiation".Treatment based on symptom differentiation is a quick method of application of classic prescriptions,which includes searching for specific symptoms or symptom groups and according to special tongue images.Treatment based on syndrome differentiation is a commonly used method in classic prescriptions,distinguishing between primary and secondary syndromes and the authenticity of cold and heat.Treatment based on disease differentiation is the inherent meaning of classic prescriptions,which is mainly to distinguish six meridian diseases and special prescriptions for specific diseases.Treatment based on person differentiation embodies the individual differences in the use of classic prescriptions,which include age,gender,constitution and abdominal syndrome.Treatment based on mechanism differentiation is an ingenious method used by classic prescriptions.When practicing clinical medicine,we should adhere to the integrated mode of"five differentiation"in the application of classic prescriptions,comprehensively considering the five dimensions,in order to improve the accuracy and effectiveness of the application of classic prescriptions,reveal and improve the academic system of classic prescriptions,and better guide their clinical application.

According to the theory of "one qi circumference"， it is believed that qi movement disorder of zang-fu organs and dysfunction of qi transformation are the pathogenesis of rheumatoid arthritis （RA）. Zang-fu organs disorder is caused by spleen-stomach depletion and dampness pathogen obstruction， while qi transformation dysfunction is due to spleen-kidney yang qi depletion. For treatment， it is recommended to put focus on regulating qi movement of zang-fu organs， and promoting qi transformation. In clinical practice， the method of fortifying spleen and removing dampness can be used to restore ascending and descending function of the center， with Shengyang Yiwei Decoction （升阳益胃汤）， Sijunzi Decoction （四君子汤）， Shenling Baizhu Powder （参苓白术散） in their modifications. The method of supplementing and replenishing liver and kidney can be used to unblock the ascending path of qi movement， with Buxue Rongjin Pill （补血荣筋丸）， Duhuo Jisheng Decoction （独活寄生汤）， Dabuyin Pill （大补阴丸）， Liuwei Dihuang Pill （六味地黄丸） in their modifications. To unblock and regulate the downward path of the waterway， it is advised to diffuse lung and direct qi downward using Guizhi Decoction （桂枝汤）， Mahuang Decoction （麻黄汤） in their modifications. To restore qi transformation function of zang-fu organs， the method of warming and tonifying spleen and kidney is recommended with formulas such as modified Sini Decoction （四逆汤） and Shenqi Pill （肾气丸）.

In the perspective of the theory of “circular movement of yang qi ascending and descending”， the author explores the four-season pathogenesis and treatment of insomnia based on the seasonal changes of the body's yin-yang balance. It is believed that the core pathogenesis of insomnia lies in the spleen and stomach deficiency and the internal buildup of dampness. The four-season pathogenesis of insomnia focuses can be categorized into four aspects： abnormal ascending of yang qi in the spring， leading to the liver fire inflammation or the liver qi stagnation； Predominance of yang qi in the upper side of the heart and gallbladder fire in the summer； Lung disorder and abnormal descent of yang qi， resulting in yang-heat conversion into dryness or disharmony between nutrient qi and defensive qi； Abnormal hiding of yang qi， manifesting as floating yang or deficiency in both yin and yang in the winter. It is advocated to dynamically grasp the pathogenesis of insomnia in accordance with the changes in time. A treatment framework called “restoring ascending and descending of yang qi” is proposed， with the core focus on resolving dampness and strengthening the spleen， while also addressing the liver and strengthen the spleen， clearing and descending the heart and gallbladder， purifing and descending the lung qi， and suppressing hyperactive the yang and invigorating the kidneys in different seasons. This enrichment of the traditional Chinese medicine time medicine research in insomnia treatment， based on the characteristics of seasonal rhythmic time， aims to better serve clinical practice and provide ideas for the clinical diagnosis and treatment of insomnia.

Review of historical literature showed that the understanding of the indicated disease location of Modified FuMai Decoction （复脉汤加减方） has evolved from the upper jiao （焦） to the middle and lower jiao. Initially， it is used for the treatment of yin deficiency of both yin and yang in the upper jiao， changes to supplement stomach and produce fluids in the middle jiao， and is used to protect yin， clear the pathogens， conslidate yin and subdue yang so as to store the true yin of lower jiao. The unchanging principle of Fumai Decoction modifications is nourishing yin， while the changing aspects are determining the secondary treatment methods based on disease location of sanjiao， concomitant disease natures， internal injury or external contraction， warm disease or cold damage， thereby choosing the corresponding added or subtracted herbs， and providing reference for the application of classical formulas.