 For those who would suggest that such objects are mere abstractions from world 2 thought processes, Popper counters that world 3 objects are necessarily more than the thought processes which have led to their creation. Theories, for example, usually have logical implications beyond anything considered by their original author, as instanced in the case of Einstein’s Special Theory of Relativity. Moreover, what is most characteristic about such objects is that, unlike world 2 mental processes, they can stand in logical relationships to each other, such as equivalence, deducibility and compatibility, which makes them amenable to the kind of critical rational analysis and development that is one of the hallmarks of science. As he puts it,