This book is an effort to bring genetic-phenomenological analyses in contact with empirical psychology, neurology, cognitive science and research in primate cognition. The first part adresses the role of weak but not arbitrary phantasy in perception, and argues that it has a transcendental function with several different aspects. Weak phantasma can be found in all fields of sensibility and at all levels of constitution. Relevant aspects of Charles-Bonnet Syndrome are analyzed in addition to the contributions of empirical psychology to our understanding of hallucinations in normal subjects. The second part is dedicated to the process of self-organization in human and animal perception from the point of view of genetic phenomenology, concentrating on the formation, change and use of the so-called types (Typus). The third part investigates whether cognition, thinking and other higher order performances of the mind - both human and animal - can be understood by taking into account the contributions of phantasmatic elements in three important fields: scenic imagination in daydreams, feelings, and co-feeling with others. To this end dual-mode theories of mind and some contributions from neurology are taken into account. The conclusion reached is that most higher-order achievements of our mind - which we tend to identify with the performance of our language-system - might in fact be accomplished without language in the low-level system of phantasmatic imagination. This leads to an inclusive theory of the subject which allows us to understand how higher-organized animals like primates can think.