This paper consists in an historical as well as conceptual analysis of the notion of experience. Following and completing Dewey, we propose to distinguish between four meanings that succeeded one another in the history of thought answering to the following designations: empirical, empiricist, experimental and experienced. The general aim is to show that the resumption of the concept by the pragmatists integrate those four meanings without their defects and limitations. 1) Experience firstly designates a kind of knowledge which is fairly reliable but related to practical purposes only, without involving any insight into the cause or reason of the occurrence, in contrast with scientific knowledge. Experience is thus conceived in opposition to the idea of reason and gets by this way a depreciatory meaning on an epistemological, moral as well as ontological level. 2) We then suggest that the empiricist way of conceiving experience makes a complete reversal of the valuation, as experience became the critical instrument of reason as far as it is the way to criticize all dogmas and doctrines that try to protect themselves from examination by claiming to be universal and necessary, that is backed up by the authority of Reason. Experience is then identified with what is given first-hand by the senses in a personal contact with nature: this characteristic of being forced upon us provides us with the guarantee we need against the vagaries of our fancy and the speculation of our reason. 3) But from a pragmatist point of view, the defect of this second meaning is to be still dependent on a dualistic conception of experience and reason that oversees their functional continuity, whereas the observation of experimental sciences may generate a renewed conception of experience. According to this view, experimentation and reasoning are two complementary and integrated stages of any activity of thought (termed the "enquiry"): each philosophical school, empiricism and rationalism, has simply selected and extracted from the complete and concrete process of thought (which is an experiencing and reasoning process) the two mythological notions of Experience and Reason supposed to be opposed to each other. 4) We show at last that a fourth conception of experience has been opposed to the experimentalist meaning in order to make room for the irreducibility of the lived and felt experience to the objective and naturalized notion derived from science (cf. bergsonism, phenomenology). In this last sense, experience denotes what is immediately experienced before all knowledge about the object of the experience. After the opposition between experience and reason, a second opposition, this time internal to the concept of experience, has to be overcome from a pragmatist point of view
