This paper provides an introduction to some of the basic concepts of the provocative French psychoanalyst Jacques Lacan. It illustrates the ways in which these concepts color the therapist's understanding of the patient as the therapist's attention is guided by the patient's expressions of thought and feeling. The response of the therapist is motivated by the interface which develops between this understanding and theoretical underpinnings. Clinical vignettes illustrating Lacan's mirror stage and his three basic orders, the Real, the Imaginary, and the Symbolic punctuate the explanations of these concepts. The paper weaves observations on the signification of language with examples of clinical interpretations.