Abstract
Traces are generally considered to constitute an ontologically distinct class of objects that can be distinguished from other objects. However, it can be observed on close inspection that the principles to demarcate traces from other objects are quite general, imprecise and intuitively unclear, except perhaps the entropic account envisaging traces as low entropy states. This view was developed by Hans Reichenbach, Adolf Grünbaum, and J. J. C. Smart on the basis of Reichenbach's theory of branch systems that are subsystems of wider systems. According to this theory, traces form within subsystems as low entropy states as a result of interaction with wider systems. It is also claimed that entropy is the measure of disorder, and that traces are ordered states. I argue that the concepts of entropy and disorder are used beyond their legitimate limits of application, for there are clear-cut counter-examples in the literature. I also analyze the concept of trace together with some examples from classical mechanics and geology in order to show that traces are determined relative to a particular context in which they are so defined