Gurudev Ranade's criticism, like Kant's criticism, is not dogmatic but constructive; the main thread of his philosophy is reconciliation. He pointed out a number of similarities between philosophical doctrines of the East and the West and always insisted on exact nomenclature. He evaluated philosophical doctrines from the standpoint of mysticism. As in the interpretation of scriptures, so in the spiritual life, tradition is important.
Gurudev Ranade's critical estimates of thinkers, both Western and Indian may be noted. Aristotle could not understand the significance of Anaximander's Apeiron. Anaximander identified Apeiron with God. Such an identification of 'the Real' and 'the Perfect' has been effected in the history of philosophy by the ontological argument.
Gurudev Ranade characterizes the philosophy of Heracleitos as rationalism and that of Parmenides as idealism. He discusses the puzzles of zeno and refers to Aristotle's and Russell's criticism of Zeno. He gives the solution of Zeno's puzzles on the basis of infinitesimal calculus. He compliments Aristotle for his scientific analysis and praises his theory of truth. He has a high regard for the mystical philosophy of Plotinus.
Gurudev greatly admires the moral philosophy of Kant. The Upanishads have a unique place in Indian philosophy and contain roots of all later philosophies. Mysticism is the culmination of Upanishadic Philosophy. The Bhagvad-Gita synthesizes the moral, the sublime and the divine in a philosophy of spirit.
A great religion like Buddhism cannot be based on the foundation of no-spirit; the Buddhistic ideal also must be interpreted in a positive way. The Jaina doctrine of relativism is good only as a tentative stage.
In Samkhya, we get intimations of the great philosophical proofs of reality. Badarayana and Samkara fail to understand the mystical significance of Sphota, which Panini alone did. Gurudev Ranade characterises Vedanta philosophy as an idealistic-spiritualistic philosophy. Though Tantrism is right in insisting on the unfoldment of vast mental power, its practices are not above censure. He further points out that mysticism has nothing to do with eroticism.
Gurudev's studies included subjects like rhetorics. He says that Vyanjana is the most fundamental process. He gives his own nine-fold scheme of Rasas where Bhakti Rasa is regarded as the Murdhanya Rasa.