Summary: Vaisesikas repudiate linguistic contention on the grounds that children and dumb persons have knowledge of objects without verbal expression. They distinguish between savikalpaka and nirvikalpaka perception, where the former involves judgment with predication and the latter does not. Naiyayikas argue that while perception manifests objects, it cannot manifest itself, requiring introspection. Nyaya identifies five kinds of doubt and three kinds of inference based on logical and psychological grounds. In terms of ordinary perception, they classify it into nirvikalpaka and savikalpaka, with the former being indeterminate and the latter determinate. The text also discusses extraordinary perception, where samanyalaksana involves perceiving a class of objects through a generic property, and argues that knowledge from testimony is inferential in character. While Naiyayikas recognize testimony as a source of knowledge, Mimansa and Vedanta consider it as self-constituted truth. Each system has a unique perspective on the nature and forms of knowledge, from perception to inference and testimony.