|S. Austin Allibone, comp. Prose Quotations from Socrates to Macaulay. 1880.|
| This word is employed by English writers in a very loose and improper sense. It is with them usually convertible into hypothesis, and hypothesis is commonly used as another term for conjecture. The terms theory and theoretical are properly used in opposition to the terms practice and practical. In this sense they were exclusively employed by the ancients; and in this sense they are almost exclusively employed by the continental philosophers.|
Sir William Hamilton.
| It is with theories as with wells: you may see to the bottom of the deepest if there be any water there, while another shall pass for wondrous profound when tis merely shallow, dark, and empty.|