  We investigate temporal and causal threads in the fabric of contemporary
physical theories with an emphasis on empirical and operationalistic aspects.
Building on the axiomatization of general relativity proposed by J. Ehlers, F.
Pirani and A. Schild and the global space-time structure elaborated by R.
Penrose, S.W. Hawking, B. Carter and others, we argue that the current way of
doing relativistic physics presupposes treating time and causality as primitive
concepts, neither of them being `more primitive' than the other. The decision
regarding which concepts to assume as primitive and which statements to regard
as axioms depends on the choice of the angle at which we contemplate the whole.
This standard approach is based on the presupposition that the concept of a
point-like particle is a viable approximation. However, this assumption is not
supported by a realistic approach to doing physics and, in particular, by
quantum theory. We remove this assumption by analysing the recent works by M.
Eckstein and T. Miller. They consider the space $P(M)$ of probability measures
on space-time $M$ such that, for an element $\mu \in P(M)$, the number $\mu
(K)$ specifies the probability of the occurrence of some event associated with
the space-time region $K$ and the measure $\mu$. In this way, $M$ is not to be
regarded as a collection of space-time events, but rather as a support for
corresponding probability measures. As shown by Eckstein and Miller, the space
$P(M)$ inherits the causal order from the underlying space-time and facilitates
a rigorous notion of a `causal evolution of probability measures'. We look at
the deductive chains creating temporal and causal structures analysed in these
works, in order to highlight their operational (or quasi-operational) aspect.
This is impossible without taking into account the relative frequencies and
correlations observed in relevant experiments.
