Tropisms

"Tropisms" are "movements of which we are hardly cognizant, [they] slip through us on the frontiers of consciousness in the form of undefinable, extremely rapid sensations. They hide behind our gestures, beneath the words we speak, the feelings we manifest, are aware of experiencing ... They ... seem to me to constitute the secret source of our existence, in what might be called its nascent state."--Foreword, p.[6].