Ideas by Edmund Husserl (1859-1938) expresses the basic concepts of a philosophical movement known as "phenomenology". Using a philosophical method that to a degree is grounded in Cartesian meditation, Husserl's philosophical system emphasizes the importance of casting away theoretical frameworks and deductive reasoning from a priori principles in favor of description of unique units of experience, or phenomena as we perceive them.
The pure perceptions that form the basis from which Husserl's inferences start, however, are not the world of common sense or experience as mediated by the Kantian synthetic a priori. Instead, he emphasizes becoming open to Being itself by setting aside preconceptions and existing habits of thought and assuming nothing.
A key feature of his philosophy is a distinction between noesis, the act of thinking or perceiving, which is a mental act, and the noemata, the things perceived, which are external to the mind. We understand what belongs to the noemata by stripping away the abstractions which are a function of our faculties and habits of conceptualization.