This informal paper studies the effects of the recent introduction of computer-generated imagery on the practice of science and its function in understanding the world. It intends to introduce the subject of computerised visualisation for scientific purposes into a wider debate, to show the diversity of issues involved—scientific, cultural and philosophical—and to build a context in which they can be critiqued. The author seeks to show the variety of scientific imaging and its influences on scientific knowledge; as both experiments and results are increasingly expressed in terms of imagery, the image assumes an integrity of its own and the object to which it refers becomes obscured. This leads to a shift of focus away from abstract theory as the embodiment of knowledge to the ascension of an allegorical image-based science with computer graphics as its natural language.