conditioning is a method that utilizes what has come to be known as the “conditional reflex phenomenon.” The following definition is given in the Oxford English Dictionary: “Conditional: subject to, depending on, or limited by, one or more conditions, not absolute.” For our purposes conditioning may be described as referring to the learning of some particular response. The conditional stimulus is one that was originally ineffective but that, after being paired with an unconditional stimulus, evokes the conditional response.