The article introduces a thematic issue of the journal Theory of Science that attempts to revive the category of "philosophi- cal toys" - objects and instruments designed for experimental scientific research that simultaneously played crucial role in the creation of the modern visual culture. It claims that to fully understand their nature and the kind of experience philosophical toys induce, it is necessary to situate their origins in eighteenth-century experimental science and aesthetics and proposes to approach them as perceptual and (...) cognitive extensions. (shrink)