Philosopher and politician, born in Inverness-shire; took his degree in medicine, but went to the London bar; was a Whig in politics; wrote "Vindiciæ Gallicæ" in reply to Burke's philippic; defended Peltier, Bonaparte's enemy, in a magnificent style, and contributed a masterly preliminary "Dissertation on Ethics" to the "Encyclopædia Britannica" (1763-1832).