Lines of Thought: Rethinking Philosophical Assumptions is a highly innovative and powerfully argued book. According to the author, noted Brazilian philosopher Claudio Costa, many philosophical ideas that today are widely seen as old-fashioned and outdated should not be dismissed, but instead should be extensively reworked and reformulated. This also means that contemporary analytical philosophy should begin to question many of its most cherished views and reconsider some of the current ways of looking at philosophy. Following this path, in the philosophy of language, the author suggests replacing the causal-historical view of proper names with a much more sophisticated form of descriptive-internalist theory able to meet Kripke's challenges. In epistemology, he argues convincingly that we should return to the old traditional tripartite definition of knowledge, reformulated in a much more complex form in which Gettier's problem would disappear. The correct response to skepticism about the external world should not be to adopt new and more fanciful views, but rather to carefully analyze the different kinds of reality attributions implied by the argument and responsible for its equivocal character. In metaphysics, he argues for a more complex reformulation of the traditional compatibilist approach of free will, relating it intrinsically with the causal theory of action and making it powerful enough to assimilate the best elements of hierarchical views. Finally, according to the author, contemporary analytic philosophy suffers from a lack of comprehensiveness. In response to this, the papers in this collection aim to restore something of a broader perspective, salvaging isolated insights by integrating them into more comprehensive views.