Paradox (literature)
Paradox, however, is essential to the structure and being of the poem. In "The Well Wrought Urn" Brooks shows that paradox was so essential to poetic meaning that paradox was almost identical to poetry. According to literary theorist Leroy Searle, Brooks' use of paradox emphasized the indeterminate lines between form and content. "The form of the poem uniquely embodies its meaning," and the language of the poem "affects the reconciliation of opposites or contraries." While irony functions within the poem, paradox often refers to the meaning and structure of the poem and is thus inclusive of irony. This existence of opposites or contraries and the reconciliation thereof is poetry and the meaning of the poem.
Gibbs paradox
In statistical mechanics, a semi-classical derivation of the entropy that does not take into account the indistinguishability of particles, yields an expression for the entropy which is not extensive (is not proportional to the amount of substance in question). This leads to a paradox known as the Gibbs paradox, after Josiah Willard Gibbs who proposed this thought experiment in 1874‒1875. The paradox allows for the entropy of closed systems to decrease, violating the second law of thermodynamics. A related paradox is the "mixing paradox". If one takes the perspective that the definition of entropy must be changed so as to ignore particle permutation, the paradox is averted.