Popper put forward a three world theory to encompass subjective knowledge and objective knowledge as well. Popper without denying the personal or subjective knowledge further argues that this should be studied from a biological or evolutionary point of view. All knowledge grows by the method of variation and selection found in living organisms. Human knowledge is adaptive and increases by conjectures and refutations. This approach from the standpoint of biology unifies Popper’s whole philosophy. The way in which Popper’s philosophy of biology contributes to the integration of thought can be seen in the new expression of the main problem of epistemology.

Popper put forward a three world theory to encompass subjective knowledge and objective knowledge as well. Popper without denying the personal or subjective knowledge further argues that this should be studied from a biological or evolutionary point of view. All knowledge grows by the method of va...