In order to characterize a thing or phenomenon from a specific point of view, it may be necessary not to find points of resemblance or association between it and some other thing or phenomenon, but to find points of sharp contrast, that is, to set one against the other, for example:
"A saint abroad, and a devil at home." (Bunyan)
"Better to reign in hell than serve in heaven." (Milton)
A line of demarcation must be drawn between logical opposition and stylistic opposition. Any opposition will be based on the contrasting features of two objects. These contrasting features are represented in pairs of words which we call antonyms, provided that all the properties of the two objects in question may be set one against another, as 'saint' -'devil', 'reign'-'serve', 'hell'-'heaven'.
Many word-combinations are built up by means of contrasting pairs, as up and down, inside and out, from top to bottom and the like.
Stylistic opposition, which is given a special name, the term antithesis, is of a different linguistic nature: it is based on relative opposition which arises out of the context through the expansion of objectively contrasting pairs, as in:
"Youth is lovely, age is lonely,
Youth is fiery, age is frosty;" (Longfellow)
Here the objectively contrasted pair is 'youth' and 'age'. 'Lovely' and 'lonely' cannot be regarded as objectively opposite concepts, but being drawn into the scheme contrasting 'youth' and 'age', they display certain features which may be counted as antonymical. This is strengthened also by the next line where not only 'youth' and 'age' but also 'fiery' and 'frosty' are objective antonyms.
It is not only the semantic aspect which explains the linguistic nature of antithesis, the structural pattern also plays an important role. Antithesis is generally moulded in parallel construction. The...