There are several faces of Four-Dimensionalism (4D). Sometimes 4D is formulated as the thesis that the material world is composed of spatial as well as temporal parts. Another version of 4D states that persisting objects are extended over time in the same way that they are extended over space. Some Four-Dimensionalists defend the thesis that all objects persist by perduring i.e. by having different temporal parts at different times. Sometimes 4D means the same as eternalism - the thesis that past and future objects (and times) are just as real as currently existing ones. Finally it can mean the thesis that all objects are in fact four-dimensional i.e. they are in every case a filling of some subregions of space-time. The author examines some varieties of 4D and tries to formulate both a precise meaning of those doctrines and an evaluation of them.
Financed by the National Centre for Research and Development under grant No. SP/I/1/77065/10 by the strategic scientific research and experimental development program:
SYNAT - “Interdisciplinary System for Interactive Scientific and Scientific-Technical Information”.