a. [f. THINK v.2 + -ABLE. Cf. UNTHINKABLE c. 1430, etc.]
1. Capable of being thought; such as one can form a notion or idea of; cogitable.
1854. H. Spencer, in Brit. Q. Rev., July, 137. A corresponding progress in language, by which greater varieties of objects are thinkable and expressible.
1883. H. Drummond, Nat. Law in Spir. W., Introd. (1884), 3. To marshal the discrete materials … into thinkable form.
2. That can be deemed real or actual; conceivable or imaginable as an existing fact.
1865. Carlyle, Fredk. Gt., XX. vi. (1872), IX. 109. How charming that you should make thinkable to us … what we were all inclined to think.
1908. Times, 10 Sept., 8/4. It is thinkable that considerate driving may render legal enactments unnecessary.
Hence Thinkableness.
1895. A. J. Balfour, Found. Belief, 286. ‘Ultimate’ scientific ideas may be unthinkable without prejudice to the ‘thinkableness’ of ‘proximate’ scientific ideas.
