The term 'creativity', meaning to produce something out of nothing, is not accurate. A definition that included the establishment, the founding or the introduction of something anew for the first time would be rather appropiate. The most accurate interpretation of the creativity process is the one proposed by Alfred Rothenberg which establishes the hypothesis that creativity is due to what he calls a 'janusian thinking' characterized by conceiving simultaneously two or more opposed ideas, images or concepts. Two examples illustrate such way of thinking: one is Einstein's General Theory of Relativity and the other is Darwin's Theory of Natural Selection. The overcome of a dualistic thinking while keeping full consciousnees, that is, the utilization of both the primary and the secondary processes postulated by Freud, would be the key to creative thinking. From a neurophysiological point of view, it is very likely that the right hemisphere is rather connected to creativity, given that it is a mental state that requires non-focalized attention, greater right hemisphere activation, and low levels of prefrontal cortical activation allowing cognitive inhibition.