The following sentence comes from Maureen Callahan’s New York Post article “Elon Musk is a Total Fraud,” dated July 21, 2018:
In March, a Tesla driver was killed while test-driving an auto-piloted Model X, the impact fully decimating half the car.
Let us ignore the passive-evasive “was killed” and let us not speculate why an “auto-piloted” sedan requires a test-driver. That way the concluding phrase might take center stage in the completeness, so to speak, of its grammatical absurdity: “The impact fully decimating half the car.”
The verb to decimate comes from Roman military practice. When a legion subdued its enemy, its commanders sometimes ordered the execution of every tenth prisoner before sending the survivors off to slavery. To decimate means to reduce by one tenth. It can also sometimes mean to reduce to one tenth, but that is an inadvisable because confusing usage. Decimation could also be punitive; a legion that fled from battle or otherwise humiliated itself in combat might suffer the decimation of its ranks as chastisement. No matter: The object of any act of decimation is a group of people. One person cannot suffer decimation, nor can half a person, nor can anything that is not a group of people.
An automobile, then, cannot suffer decimation. Still less can half an automobile suffer decimation, even if it were a Tesla. Decimation, moreover, has no degrees. The phrase full decimation would therefore be a pleonasm, and not the good kind. General Maximus either decimates the captured Thracian army or he offers his lenience. The Thracians would prefer, of course, that he offer his lenience.
It is probable that Callahan, like many people, regards decimation as an exotic synonym for destruction although, in its precision, it is not. To destroy, equally with to decimate, possesses a Latin origin but it has so thoroughly assimilated itself to English as to appear, basely, Anglo-Saxon. To decimate, by contrast, retains its slightly foreign, slightly antique, slightly graduate-schoolish aura of sophistication. Even supposing that Callahan seizes on decimation because she thinks it a synonym of destruction, however, and even supposing that she wants to seem educated in her vocabulary, the problem of the fully destroyed half a car remains to be solved. Notice that the test-collision to which Callahan refers in her article implicitly left half of that same Tesla, as she might write, fully intact – or rather, intact, omitting any qualification as to degree. For intactness has no more degrees than decimation. One wonders how many degrees Callahan boasts. She should ask for a partial refund on at least half of fully one of them.