Perception is an active process involving a complex system of perceptual and cognitive structures. Facts reflect the ways in which we organise the data received by our senses, and this organisation is highly selective. The private theories of psychoanalysis play a major role in the organisation of facts and in their conceptualisation. It is important that there should be more attention to clinical theories and technical frames of reference, and as an illustration of this a clinico-technical conceptualisation which has been found useful is presented in some detail. This makes use of the concepts of the present and past unconsciouses, in this way emphasising the topographical dimension which had come to be under-stressed in Freud's structural theory and in subsequent ego psychology. The past unconscious can be regarded as a sort of 'template' (structures, rules, schemata, etc.) developed in the child in the first few years of life. This contributes to the form of fantasies and behaviour arising in the depths of the present unconscious, in which system such representational content is acted on by defences and other mechanisms to prevent 'child-like' content from disrupting the older individual's equilibrium. The censorship between the present unconscious and consciousness is considered, and the view taken that the primary focus of the analytic work is in relation to this censorship. The links between the analytical aim of making previously unacceptable mental content acceptable to the individual, on the one hand, and the roles of construction and reconstruction, on the other, are discussed in relation to psychoanalytic technique.