origin of the world and of the path which man has to tread with a view to obtain liberation. Inspired by this teaching, both the orthodox and the heterodox classes of thinkers set themselves to work. The orthodox thinkers still hold to the Veda as the standard by which the truth of the results of their intellectual speculation should be measured, and in course of time they add to the Veda the fresh block of teachings as part and parcel of it under the name of Upanishads; while the heterodox, carrying on their old reactionary spirit against ritualism into the realm of theosophy, deny all authority to Revelation as such. The orthodox thought assumes in course of time the forms of Vaiseshika, Nyaya, Sankhya, and Yoga systems, while the heterodox thought gives birth in the long run, to something like the Buddhistic and Arhata (Jain) systems of philosophy.

15. The thinkers of orthodox type try to cast all the knowledge they have acquired by Revelation into a systematic form. The chief object of their attempt at systematisation is to overthrow the materialistic system of Charvaka; and for this they have to perfect their logic. They have accordingly developed a complete system of logic by which they seek to establish the truths contained in the scripture independently of all aid from scripture. In their zeal to silence the Charvakas

who recognise no other source of knowledge than pratyaksha or sensuous perception, they have given undue prominence to anumana or empirical inference as the one sufficient instrument by which all things worth knowing can be known and proved. When the scripture is apparently at variance with the findings of logic, it is so interpreted as not to offend the conclusions alleged to have been arrived at by independent reasoning.--I say 'alleged' because it is the Revelation which has made them think of the soul, God, etc., whose existence could never have been suggested by mere empirical reasoning. This method of investigation cannot but vitiate thee system, so far as it relates to the subject which falls within the special province of Revelation. The laws of reasoning are primarily based on relations of agreement and difference among external objects, and as such they may hold good when dealing with things which are experienced as external to the entity that perceives them, and which thus fall within the ken of the sense-organs by which impressions of external objects are received. They are found most potent instruments in finding out the relations of one object to. another in the external world, and all sciences relating to gross material things outside the Self are based on those laws. But when the same laws are rigorously applied to things beyond the ken of sense-organs, especially when they are