Certain philosophers have described man as a cooking animal, others as a tool-making animal, others, again, as a laughing animal. No creature save man, say the advocates of the last definition, seems to have any "sense of humour." However this may be, there can be little doubt that man in all ages of which we have any knowledge has possessed that faculty which perceives ridiculous incongruities in the relative positions of certain objects, and in the actions and sayings of individuals, which we term the "sense of the ludicrous." It is not to be supposed that a dog or a cat--albeit intelligent creatures, in their own ways--would see anything funny or laughable in a man whose sole attire consisted in a general's hat and sash and a pair of spurs! Yet _that_ should be enough to "make even a cat laugh"! Certainly laughter is peculiar to our species; and gravity is as certainly not always a token of profound wisdom; for The gravest beast's an ass; The gravest bird's an owl; The gravest fish's an oyster; And the gravest man's a _fool_. Many of the great sages of antiquity were also great humorists, and laughed long and heartily at a good jest. And, indeed, as the Sage of Chelsea affirms, "no man who has once heartily and wholly laughed can be altogether, irreclaimably bad. How much lies in laughter!--the cipher key wherewith we decipher the whole man!... The man who cannot laugh is not only fit for treasons, stratagems, and spoils, but his whole life is already a treason and a stratagem." Let us, then, laugh at what is laughable while we are yet clothed in "this muddy vesture of decay," for, as delightful Elia asks, "Can a ghost laugh? Can he shake his gaunt sides if we be merry with him?"