by ear Relying on an innate sense of what sounds or feels right; without referring to, or depending upon prescribed procedures or written music. This use of ear, referring to an ability to recognize musical intervals, dates from the early 16th century. At that time, play it by ear meant to sing or play an instrument without printed music. By the 19th century, the same phrase came to mean to proceed one step at a time, trusting intuition and a subtle sense of timing, rather than a prearranged plan, to determine the proper course of action.

Both this figurative use and the earlier one heard in musical contexts are current today.

by the seat of one’s pants By instinct or intuition; just barely, narrowly. This expression was originally an aviation term meaning to fly without instruments, and thus to be forced to rely upon the instincts acquired through past experience. The sense of ‘just barely, narrowly’ would seem to be an outgrowth of this aviation use, since a pilot flying by the seat of his pants is apt to escape disaster by a very narrow margin.

feel in one’s bones To intuit; to sense something before it becomes apparent. This expression probably stems from the ability of people who suffer from bone diseases such as arthritis and rheumatism to predict changes in the weather because of increased pain. This ability is due to the fact that changes in atmospheric pressure and humidity may affect the bones and joints of such individuals. Since changes in pressure and humidity often precede a change in the weather, these people seem to sense the change before it becomes apparent. In its current usage, feel in one’s bones is no longer limited to people with bone disorders or to changes in the weather.

follow one’s nose To be guided by instinct, to play it by ear. The expression clearly derives from an animal’s keen and usually unerring sense of smell. The phrase was used figuratively as early as 1692 by Richard Bentley in one of his Boyle lectures:

The expression also has the similar but somewhat less figurative meaning of ‘go straight forward, continue on in a direct course.’

know which way the wind blows See SHREWDNESS.

a little bird An undisclosed source; a secret witness; intuition. This phrase refers to the ubiquitous yet unobtrusive nature of a small bird that, theoretically at least, is able to observe many covert goings-on as it flies through the air. Since the beginning of recorded history (and no doubt before), birds have been respected and, at times, revered for their godlike powers of flight and sight. Many Greek and Roman soothsayers cited their purported understanding of avian language as a source of their knowledge and intuitive or psychic abilities. According to the Koran, the sacred book of Islam, Solomon was advised of Queen Sheba’s activities by a tiny lapwing, and Muhammad himself was counseled by a pigeon. In addition, some early religious woodcuts show various popes listening to the whispered advice of a small bird. These and many other legends have given rise to the almost universal adage, a little bird told me, an expression indicating that the speaker knows a secret or other confidential matter by virtue of intuition or some undisclosed source.

my little finger told me that See OMEN.

rule of thumb See CRITERION.

a shot in the dark A wild guess; a random conjecture. This widely used expression combines shot ‘an attempt’ with the phrase in the dark ‘uninformed’ to imply that a given conjecture is made without the benefit of relevant information or assistance. In most cases, however, a “shot in the dark” does involve an element of intuitive reasoning. “Shot in the Dark” was the title of an amusing 1964 movie that starred Peter Sellers as the bumbling Inspector Jacques Clouseau.