In contrast to classical philosophy, which places the mind and rationality in the centre of cognition of the world, post-classical philosophy denies that the mind is the basis of reality and regards the irrational as primary: without intuitive perception, cognition of the world is believed to be limited and incognisable. This view was supported by Kant and further developed in Bergson's philosophy, which significantly influenced Latvian poets and thinkers, such as Barda and Ziedonis. They believed that a literary image cannot be expressed in a logical, rational form; rather, its only form of expression is the imagistic form given to it by the artist. The irrational in art is regarded as a problem of perception: the same work of art can be comprehensible and familiar to one perceiver but incomprehensible and alien, and thus irrational, to another. The problem of perception as the irrational is obvious in the symbolism of modernism, which was introduced by French poets in the 1980s. Since the end of the 1950s, rationalisation of the irrational has become a widespread trend in philosophy; that is, it extends cognition to areas that previously were considered incognisable. This view had already been expressed by Kant and Bergson, as well as Barda and Ziedonis, whose works reveal intuitive rationalism.