This chapter of the book on philosophy deals with philosophy, in general, as it relates to psychology, and also it deals more specifically with key topics in philosophy in relation to causality and to free will. Some of the positions broached include the distinctions between reductionism and constructivism, causalism and acausalism, and determinism and compatibilism (also libertarian and semi-compatibilist views). Some of the particular, intermediate, or integrative positions considered include eliminative reductionism, elemental constructivism, criterial causation, and probabilistic adeterminism. The opposition between positivism and relationism is treated toward the end of the chapter. The smorgasbord of philosophical viewpoints continues with discussion of ones for reductionism (moderate, constitutive, neo), constructivism (emergent, situated, neo), dualism (property), positivism (neo), determinism (hard, soft), compatibilism (semi), and dispositionalism. The chapter explores brain-based research related to free will, including intrinsic networks. It presents a model termed “apparent” mental causation.