It starts by where is classical conditioning going to take place is the first question. Classical conditioning is a type of learning that had a major influence on the school of thought. In order for it to take place the conditioned stimulus is what must take place after the unconditioned stimulus. Its important to note that classical conditioning involves placing a neutral sign before a naturally occurring reflex. Discovered by Russian psychologist Ivan Pavlov, classical conditioning occurs though associations between and environmental stimulus and a naturally occurring stimulus.