In the second place it is said that the Indians had no proper and accurate historical records and biographies and it is therefore impossible to write a history of Indian philosophy. This objection is also partially valid. But this defect does not affect us so much as one would at first sight suppose; for, though the dates of the earlier beginnings are very obscure, yet, in later times, we are in a position to affirm some dates and to point out priority and posteriority in the case of other thinkers. As most of the systems developed side by side through many centuries their mutual relations also developed, and these could be well observed. The special nature of this development has been touched on in the fourth chapter. Most of the systems had very early beginnings and a continuous course of development through the succeeding centuries, and it is not possible to take the state of the philosophy of a particular system at a particular time and contrast it with the state of that system at a later time; for the later state did not supersede the previous state, but only showed a more coherent form of it, which was generally true to the original system but was more determinate. Evolution through history has in Western countries often brought forth the development of more coherent types of philosophic thought, but in India, though the types remained the same, their development through history made them more and more coherent and determinate. Most of the parts were probably existent in the earlier stages, but they were in an undifferentiated state; through the criticism and conflict of the different schools existing side by side the parts of each of the systems of thought became more and more differentiated, determinate, and coherent. In some cases this development has been almost imperceptible, and in many cases the earlier forms have been lost, or so inadequately expressed that nothing definite could be made out of them. Wherever such a differentiation could be made in the interests of philosophy, I have tried to do it. But I have never considered it desirable that the philosophical interest should be subordinated to the chronological. It is no 6