This study emphasizes the problem of truth, reality, and language, highly philosophical notions, as they are expressed in Jumpers (1972) by the contemporary British playwright, Tom Stoppard (1937: 87 years old). Basing our analysis on some theories of analytical philosophy and the postmodern thought, we show how Stoppard stresses, in his aforementioned play, the problem of knowledge or truth in a context where old certainties have collapsed. After displaying the intrinsic link between truth, reality, and language from a historical and philosophical perspective, the study focuses on the relativity of human knowledge, particularly with regard to questions of an ethical and/or metaphysical nature. It also shows that reality is ultimately only the subjective interpretation or representation that individuals have of facts and things. This means that it only exists in subjective consciousness and is, from this point of view, always elusive.