Russell has distinguished two kinds of propositions: Atomic & Molecular.
A conjunction of two or more atomic propositions produces a molecular proposition. Thus, a molecular proposition has as its parts the atomic propositions. Explaining molecular propositions, Russell says:
“I call them molecular propositions because, they contain other propositions which you may call their atoms, and by molecular propositions I mean propositions having such words as ‘or, ‘if, ‘and’ and so forth.” The words ‘or1, ‘if “an’ etc. Which are used to conjoin atomic propositions is called logical connectives.
Each molecular proposition must have at least one logical connective. Some examples of molecular propositions are giving below
1. Either it is raining or it is snowing.
2. If there is noise, the baby will get up.
3. It was cloudy and, I brought my umbrella.
4. God willing I shall be victorious
5. You cannot trust Mohan or Sohan because, both are compulsive liers. The kinds of molecular propositions are determined by the kinds of logical connective. The most important of these are “an”, “or” and “If then”. Accordingly, the kinds of molecular propositions are also three:
(2) Disjunctive and