Scientists try to uncover the mental mechanisms that allow us to see, feel, touch, etc. They are helped by philosophers, who elaborate characterizations of perception, of its function and nature. Yet, perception, as a scientific object, is quite vague. In particular, perception is hard to circumscribe in the architecture of the mind. The aim of this dissertation is to shed light on the kind of scientific object perception is, through a philosophical work based on analytical philosophy of mind, philosophy of science and on current philosophical developments concerning perception. How could we know that a specific phenomenon is a perceptual one? How does the scientist know that she is studying perception and not another activity of the mind? What are the boundaries of perception? These questions have direct implications in everyday scientific practice, especially in the interpretation of experimental results. They also pertain to philosophical debates such as the cognitive penetrability of perception. In this dissertation, I first explore the usual method for determining the boundaries of perception, based on the idea that perception is a natural kind of mental states. I then elaborate another strategy called "conceptual engineering". In this strategy, I study perception as a scientific concept. I show that there are at least four different concepts of perception. I argue in favor of conceptual pluralism, i.e. that these concepts of perception are all legitimate. This pluralism is part of a classical process commonly undergone by scientific concepts - conceptual fragmentation – in which a scientific concept is fragmented into several sub-concepts. In a third part, I explore metaphysical foundations for the boundaries of perceptions. I show that there are several alternative ways to metaphysically ground the boundaries of perception. The choice between them influence how empirical results are interpreted. Finally, I argue that the concept of perception should be today considered an organizational concept in cognitive science, whose main function is to guide, coordinate and integrate interdisciplinary research about perception. Recognizing this specific place of the concept perception in scientific and philosophical investigations about the mind would contribute to enrich discussions, as well as to avoid ill-posed questions and fruitless debates.