What is another word for "theory"?

Roget's Thesaurus (1911) lists these synonyms for "theory": accessible, achievable, admit, agreement, analogy, and, anything, approximation, are, association, assumed, assumption, attainable, bare, barely, bear, belief, blue, but, chance, compatibility, compatible, conceit, conceivable, condition, conjecture, contingency, contingent, credible, dark, data, dice, distance, divination, doubtful, effect, estimate, feasibility, feasible, guess.