The aim of this dissertation is to provide a non-reductive account of cognitive phenomenology and the experience of thinking. The nature of conscious thought is an issue that has occupied philosophers since ancient times, and still many questions in this domain remain unanswered. One of them is the relation between thought and experience or phenomenal consciousness, in the particular way explored in this thesis: when we undergo a certain cognitive mental episode, should we recognize an experience like our other sensory, perceptual, or emotional experiences or should we rather recognize a very different sort of experience? Experiences are usually characterized by a phenomenal character or what-it-is-likeness for the subject to undergo them, which is usually taken as the mark of phenomenal consciousness and which, for mainstream contemporary philosophy of mind, has been limited to sensory and perceptual experiences, or even to emotional experiences. My general thesis is that conscious thought should be included in the domain of phenomenal consciousness and that there is an experience of thinking or conscious thought with a specific phenomenal character, namely, a phenomenal character that cannot be reduced to other non-cognitive kinds of phenomenologies. The thesis has three main parts, which are divided in several chapters. In the first part, Introduction, I present the basic elements to be able to start the investigation. I firstly clarify the relevant issues involved in the debate (Chapter 1), I justify the terminology chosen and I present the main views and a brief history of the problem. I then propose a way to approach the experience of thinking from a methodological point of view (Chapter 2), through a study of some methodological problems in philosophy and psychology, mainly related to introspection and introspective evidence. In the second part of the thesis, Main Arguments in Cognitive Phenomenology, I defend my non-reductive view with several arguments. I present the obvious argument (Chapter 3) for the conclusion that conscious thoughts have phenomenal properties and I resist some putative cases against the argument. I then present my version of the phenomenal argument (Chapter 4), which shows that there is a phenomenal change between two cognitive experiences contrasted and that this change cannot be explained by appealing to the sensory/emotional elements that by hypothesis remain constant. My presentation of this argument is complemented by a defense against some restrictivist views (Chapter 5). I then present the epistemic argument, which claims that we have introspective immediate knowledge of the kind of mental episode we are in (and of different cognitive atittudes), and that this would not be possible unless cognitive episodes have a specific cognitive phenomenology (Chapter 6). I finally consider another argument, the ontological argument, that might support the reductionist view , but I argue that it does not succeed (Chapter 7). In the third part of the thesis, The Specification of Cognitive Phenomenology, and as a further step in the discussion, I propose a specification of cognitive phenomenology in relation to intentionality and its two main components in conscious thought, cognitive content (Chapter 8) and cognitive attitude (Chapter 9). This proposal provides us with a way of determining similarities and differences in cognitive phenomenology that result in different experiential kinds and different types of conscious thought in virtue of their phenomenology. Moreover, it offers an answer to the question of the relation of determination between both components and their phenomenal character. This dissertation questions well some well-established assumptions in philosophy of mind and consciousness studies: (i) it implies a comprehension of phenomenal consciousness as including cognition, (ii) it rejects the assymetry between sensory/perceptual experience and cognitive one (regarding temporal structure and specification attempts) and (iii) it questions separatist positions between intentionality and phenomenal consciousness. It also opens new research in relation to other philosophical topics and empirical studies and it contributes to the examination of two research fields (consciousness and cognition) that have normally been investigated separately. / L’objectiu d’aquesta tesi és presentar una teoria no reductivista de la fenomenologia cognitiva i de l’experiència del pensament. La naturalesa del pensament conscient és una qüestió que ha preocupat als filòsofs des de l’antiguitat i un àmbit on encara trobem moltes qüestions que no tenen resposta. Una d’elles és la relació entre el pensament i l’experiència o la consciencia fenomènica, en el sentit particular que exploro en aquesta tesi: quan tenim una experiència d’un cert episodi mental cognitiu, es tracta d’una experiència com les altres experiències sensorials, perceptives o emocionals, o bé es tracta d’un tipus molt diferent d’experiència? Les experiències normalment es caracteritzen per tenir un caràcter fenomènic o un “com a què és” (what it is like) pel subjecte tenir aquestes experiències, que es prèn com la marca de la consciència fenomènica i que, en filosofia contemporània de la ment, generalment es restringeix a les experiències sensorials, perceptives o, fins i tot, emocionals. La tesi general que defenso és que el pensament conscient ha de ser inclòs en l’extensió de la consciència fenomènica i que existeix una experiència de pensament conscient amb un caràcter fenomènic específic, és a dir, un caràcter fenomènic que no es pot reduir a altres tipus de fenomenologies. Aquesta conclusió general qüestiona alguns supòsits ben establerts en filosofia de la ment i estudis sobre consciència, i així obre la porta a noves investigacions en aquesta direcció. Per tal de defensar aquesta teoria no reductivista, primerament clarifico les qüestions rellevants en el debat i examino com hem d’aproximar-nos a l’experiència del pensament (Capítols 1 i 2). En segon lloc, presento una sèrie d’arguments a favor de la meva tesi (Capítols 3, 4 i 6) i argumento en contra d’estratègies restrictivistes (Capítols 5 i 7). Finalment, com a un pas més en la discussió, proposo una especificació de la fenomenologia cognitiva en relació a la intencionalitat i els seus dos components principals en el pensament conscient, el contingut cognitiu (Capítol 8) i l’actitud cognitiva (Capítol 9), oferint respostes a la qüestió de la relació de determinació entre ambdós components i el seu caràcter fenomènic.